Three-dimensional printing

ABSTRACT

Disclosed herein are kits, methods, systems, and compositions for threedimensional printing. In an example, disclosed herein is a multi-fluid kit for threedimensional printing comprising: a marking agent comprising a marking component which is a fluorescent color agent that is activated by ultraviolet radiation to emit light in the visible range of from about 400 nm to about 780 nm; a first fusing agent; a second fusing agent different from the first fusing agent; and a detailing agent.

BACKGROUND

Three-dimensional (3D) printing may be an additive printing process usedto make three-dimensional solid parts from a digital model. 3D printingis often used in rapid product prototyping, mold generation, and moldmaster generation. Some 3D printing techniques are considered additiveprocesses because they involve the application of successive layers ofmaterial. This is unlike traditional machining processes, which oftenrely upon the removal of material to create the final part. Materialsused in 3D printing often include curing or fusing, which for somematerials may be accomplished using heat-assisted extrusion orsintering, and for other materials may be accomplished using digitallight projection technology.

BRIEF DESCRIPTION OF THE DRAWINGS

Features of examples of the present disclosure will become apparent byreference to the following detailed description and drawings, in whichlike reference numerals correspond to similar, though perhaps notidentical, components. For the sake of brevity, reference numerals orfeatures having a previously described function may or may not bedescribed in connection with other drawings in which they appear.

FIG. 1 is flow diagram illustrating an example of a 3D printing methodsaccording to the present disclosure.

FIG. 2 is a simplified isometric view of an example of a 3D printingsystem according to the present disclosure.

FIG. 3 is a photograph showing a 3D printed part according to anexample.

DETAILED DESCRIPTION

The present disclosure refers herein to multi-fluid kits for 3Dprinting, 3D printing kits, 3D printing compositions, 3D printingsystems, and 3D printing methods.

In some examples, disclosed herein is a multi-fluid kit forthree-dimensional printing comprising: a marking agent comprising amarking component which is a fluorescent color agent that is activatedby ultraviolet radiation to emit light in the visible range of fromabout 400 nm to about 780 nm; a first fusing agent; a second fusingagent different from the first fusing agent; a detailing agent; and amarking agent.

In some examples, the fluorescent color agent is substantially invisiblein ambient light.

In some examples, the fluorescent color agent comprisesdistyrylbenzenes, distyrylbiphenyls, divinylstilbenes,triazinylaminostilbenes, stilbenyl-2H-triazoles, benzoxazoles, furans,benzo[b]furans, benzimidazoles, 1,3-diphenyl-2-pirazolines, coumarins,naphthalimides, organic europium (III) complexes, fluorescein,rhodamines, or mixtures thereof.

In some examples, the fluorescent color agent is activated byultraviolet radiation in the range of from about 200 nm to about 400 nm.

In some examples, the fluorescent color agent compriseshexasodium-2,2′-[vinylenebis[3-sulfonato-4,1-phenylene)imino[6-(diethylamino)-1,3,5-triazine4,2-diyl]imino]]bis(benzene-1,4-disulphonate).

The marking agent can be used to form 3D printed parts for the purposeof part tracking, security marking, and/or other several applicationsthat can require uniquely identifying 3D printed parts.

The first fusing agent comprises at least one nanoparticle, wherein thenanoparticle comprises at least one metal oxide, which absorbs infraredlight in a range of from about 780 nm to about 2300 nm and is shown informula (1): MmM′O (1) wherein M is an alkali metal, m is greater than 0and less than 1, M′ is any metal, and n is greater than 0 and less thanor equal to 4; and wherein the nanoparticle has a diameter of from about0.1 nm to about 500 nm.

The multi-fluid kit further comprises: at least one color agent.

The second fusing agent comprises a near infrared absorbing compound.

The near infrared absorbing compound is selected from the groupconsisting of carbon black, oxonol, squarylium,chalcogenopyrylarylidene, bis(chalcogenopyrylo)polymethine,bis(aminoaryl)polymethine, merocyanine, trinuclear cyanine,indene-crosslinked polymethine, oxyindolidine, iron complexes, quinoids,nickel-dithiolene complex, cyanine dyes, and combinations thereof.

The detailing agent comprises at least 70 wt % water based on the totalweight of the detailing agent.

The color agent comprises: a cyan ink agent; a yellow ink agent; amagenta ink agent; and a black ink agent.

In some examples, disclosed herein is a three-dimensional printing kitcomprising: a powder build material, wherein the powder build materialis selected from the group consisting of polymeric powder,polymeric-ceramic composite powder, and combinations thereof; a markingagent comprising a marking component which is a fluorescent color agentthat is activated by ultraviolet radiation to emit light in the visiblerange of from about 400 nm to about 780 nm; a first fusing agent; and asecond fusing agent different from the first fusing agent.

The three-dimensional printing kit further comprises: a detailing agent;and at least one color agent.

In some examples, the fluorescent color agent is activated byultraviolet radiation in the range of from about 200 nm to about 400 nm.

In some examples, the fluorescent color agent compriseshexasodium-2,2′-[vinylenebis[3-sulfonato-4,1-phenylene)imino[6-(diethylamino)-1,3,5-triazine4,2-diyl]imino]]bis(benzene-1,4-disulphonate).

In some examples, disclosed herein is a method of using thethree-dimensional printing kit, the method comprising: adding the powderbuild material, the marking agent, the first fusing agent, and thesecond fusing agent of claim 10 to a three-dimensional printer; andprinting a three-dimensional part.

In some examples, disclosed herein is a method for three-dimensionalprinting comprising: (i) depositing a layer of a polymeric powder buildmaterial on a build platform; (ii) based on a 3D object model,selectively applying a first fusing agent, a second fusing agentdifferent from the first fusing agent, a marking agent, a detailingagent, and at least one coloring agent, to at least a portion of thelayer of the polymeric powder build material; (iii) repeating (i) and(ii) at least one time to form an intermediate part; and (iv) heatingthe intermediate part to a temperature of up to about 180° C. to form athree-dimensional printed part, wherein the marking agent comprises amarking component which is a fluorescent color agent that is activatedby ultraviolet radiation to emit light in the visible range of fromabout 400 nm to about 780 nm.

The method of three-dimensional printing further comprises: decaking thethree-dimensional printed part.

Examples of the multi-fluid kits for 3D printing, 3D printing kits, 3Dprinting compositions, 3D printing systems, and 3D printing methodsdisclosed herein can include exposing an entire layer of a buildmaterial (also referred to as build material particles) to radiation andfusing/hardening a selected region (in some instances less than theentire layer) of the build material to become a layer of a 3D part (or3D object or article). A fusing agent can selectively be deposited incontact with the selected region of the build material. The fusing agentcan be capable of penetrating into the layer of the build material andspreading onto the exterior surface of the build material.

This fusing agent can be capable of absorbing radiation and convertingthe absorbed radiation to thermal energy, which in turn melts or sintersthe build material that is in contact with the second fusing agent. Thiscauses the build material to fuse, bind, cure, etc. to form the layer ofthe 3D part (or 3D object or article). The fusing agents used in multijet fusion tend to have significant absorption (e.g., 80%) in thevisible region (400 nm-780 nm).

The multi-fluid kits for 3D printing, 3D printing kits, 3D printingcompositions, 3D printing systems, and 3D printing methods disclosedherein can use two different fusing agents: a low tint fusing agent(first fusing agent) and a core fusing agent (second fusing agent). Insome examples, the absorption of the second fusing agent generates heatsuitable for fusing during 3D printing, which leads to 3D parts havingmechanical integrity and relatively uniform mechanical properties (e.g.,strength, elongation at break, etc.). This absorption, however, alsoresults in strongly colored, e.g., black, 3D parts. In some otherexamples, the absorption of a first fusing agent is used instead of thesecond fusing agent to build the entire 3D part. This example of thefirst fusing agent includes metal oxide nanoparticles. The first fusingagent are a plasmonic resonance absorber, having absorption atwavelengths ranging from 800 nm to 4000 nm and transparency atwavelengths ranging from 400 nm to 780 nm.

As used herein “absorption” means that at least 80% of radiation havingwavelengths ranging from 800 nm to 4000 nm is absorbed. Also usedherein, “transparency” means that 20% or less of radiation havingwavelengths ranging from 400 nm to 780 nm is absorbed. This absorptionand transparency allows the first fusing agent to absorb enoughradiation to fuse the build material in contact therewith while causingthe 3D part to be white or slightly colored.

Other examples of the compositions, methods, and systems disclosedherein utilize a combination of different fusing agents (e.g., thesecond fusing agent and the first fusing agent) to build a part having acore (innermost layers or region) with mechanical integrity and havingan exterior (outermost layers or region) with color (i.e., white or somecolor other than black).

3D Printing Method

In some examples, as illustrated in FIG. 1, disclosed is a method forthree-dimensional printing (100) comprising: (i) depositing a layer of apolymeric powder build material on a build platform (110); (ii) based ona 3D object model, selectively applying a first fusing agent, a secondfusing agent different from the first fusing agent, a marking agent, anda detailing agent, to at least a portion of the layer of the polymericpowder build material (120); (iii) repeating (i) and (ii) at least onetime to form an intermediate part (130); and (iv) heating theintermediate part to a temperature of up to about 180° C. to form athree-dimensional printed part (140), wherein the marking agentcomprises a marking component which is a fluorescent color agent that isactivated by ultraviolet radiation to emit light in the visible range offrom about 400 nm to about 780 nm.

Within such three-dimensional (3D) printing methods, the first fusingagent and the second fusing agent enhance the absorption of theradiation, convert the absorbed radiation to thermal energy, and promotethe transfer of the thermal heat to the build material particles incontact therewith.

In an example, the first fusing agent and the second fusing agentsufficiently elevate the temperature of the build material particlesabove the melting or softening point of the particles, allowing fusing(e.g., sintering, binding, curing, etc.) of the build material particlesto take place. Exposure to electromagnetic radiation forms a layer ofthe 3D part/object. Such a layer could be a colored layer when a coloredink composition is further applied, either simultaneously with the firstfusing agent and/or second fusing agent, or subsequently. It is to beunderstood that portions of the build material that do not have thefirst fusing agent or the second fusing agent applied thereto do notabsorb enough energy to fuse.

3D Printing System

The three-dimensional printing compositions, described herein, areprinted and methods, described herein, carried out using athree-dimensional printing system described herein. An example of a 3Dprinting system 200 is depicted in FIG. 2. It is to be understood thatthe 3D printing system 200 may include additional components and thatsome of the components described herein may be removed and/or modified.Furthermore, components of the 3D printing system 200 depicted in FIG. 2may not be drawn to scale and thus, the 3D printing system 200 may havea different size and/or configuration other than as shown therein.

The printing system 200 includes a build area platform 202, a buildmaterial supply 204 containing build material particles 206, and a buildmaterial distributor 208. The build area platform 202 receives the buildmaterial particles 206 from the build material supply 204. The buildarea platform 202 may be integrated with the printing system 200 or maybe a component that is separately insertable into the printing system200. For example, the build area platform 202 may be a module that isavailable separately from the printing system 200. The build materialplatform 202 that is shown is also one example, and could be replacedwith another support member, such as a platen, a fabrication/print bed,a glass plate, or another build surface.

The build area platform 202 may be moved in a direction as denoted bythe arrow 210, e.g., along the z-axis, so that build material particles206 may be delivered to the platform 202 or to a previously formed partlayer. In an example, when the build material particles 206 are to bedelivered, the build area platform 202 may be programmed to advance(e.g., downward) enough so that the build material distributor 208 canpush the build material particles 206 onto the platform 202 to form asubstantially uniform layer of the build material particles 206 thereon.The build area platform 202 may also be returned to its originalposition, for example, when a new part is to be built. The buildmaterial supply 204 may be a container, bed, or other surface that is toposition the build material particles 206 between the build materialdistributor 208 and the build area platform 202. In some examples, thebuild material supply 204 may include a surface upon which the buildmaterial particles 206 may be supplied, for instance, from a buildmaterial source (not shown) located above the build material supply 204.Examples of the build material source may include a hopper, an augerconveyer, or the like. Additionally, or alternatively, the buildmaterial supply 204 may include a mechanism (e.g., a delivery piston) toprovide, e.g., move, the build material particles 206 from a storagelocation to a position to be spread onto the build area platform 202 oronto a previously formed part layer.

The build material distributor 208 may be moved in a direction asdenoted by the arrow 211, e.g., along the y-axis, over the buildmaterial supply 204 and across the build area platform 202 to spread alayer of the build material particles 206 over the build area platform202. The build material distributor 208 may also be returned to aposition adjacent to the build material supply 204 following thespreading of the build material particles 206. The build materialdistributor 208 may be a blade (e.g., a doctor blade), a roller, acombination of a roller and a blade, and/or any other device capable ofspreading the build material particles 206 over the build area platform202. For instance, the build material distributor 18 may be acounter-rotating roller.

As shown in FIG. 2, the printing system 200 also includes an inkjetapplicator 214A, which may contain examples of the first fusing agent216. As depicted in FIG. 2, some examples of the printing system 200 mayinclude at least one additional applicator 214B and/or 214C and/or 214D.In one example, the printing system 200 includes applicator 214B, whichmay contain a second fusing agent 218, in addition to the inkjetapplicator 214A. In another example, the printing system 200 includesinkjet applicator 214C, which may contain a color agent 230, in additionto the inkjet applicator 214A and/or 214B. In another example, theprinting system 200 includes inkjet applicator 214D, which may contain adetailing agent 220, in addition to the inkjet applicator 214A and/or214B and 214C.

In some examples, the printing system 200 includes another inkjetapplicator 214E, which may contain a marking agent.

In some examples, the printing system 200 includes inkjet applicators214A, 214B, 214C, 214D, and/or 214E.

The inkjet applicator(s) 214A, 2146, 214C, 214D, and 214E may be scannedacross the build area platform 202 in the direction indicated by thearrow 212, e.g., along the y-axis. The inkjet applicator(s) 214A, 214B,214C, 214D, and 214E may be, for instance, a thermal inkjet printheadand/or a piezoelectric printhead, and may extend a width of the buildarea platform 202. While each of the inkjet applicator(s) 214A, 214B,214C, 214D, and 214E is shown in FIG. 2 as a single applicator, it is tobe understood that each of the inkjet applicator(s) 214A, 2146, 214C,214D, and 214E may include multiple inkjet applicators that span thewidth of the build area platform 202. Additionally, the inkjetapplicator(s) 214A, 214B, 214C, 214D, and 214E may be positioned inmultiple printbars. The inkjet applicator(s) 214A, 214B, 214C, 214D, and214E may also be scanned along the x-axis, for instance, inconfigurations in which the inkjet applicator(s) 214A, 214B, 214C, 214D,and 214E does/do not span the width of the build area platform 202 toenable the inkjet applicator(s) 214A, 214B, 214C, 214D, and 214E torespectively deposit the first fusing agent 216, the second fusing agent218, the color agent 230, the detailing agent 220, and the marking agent222, over a large area of a layer of build material particles 206. Theinkjet applicator(s) 214A, 214B, 214C, 214D, and 214E may thus beattached to a moving XY stage or a translational carriage (neither ofwhich is shown) that moves the inkjet applicator(s) 214A, 2146, 214C,214D, and 214E adjacent to the build area platform 202 in order todeposit the respective fluids 216, 218, 230, 220, and 222 inpredetermined areas of a layer of the build material particles 206 thathas been formed on the build area platform 202 in accordance with themethod(s) disclosed herein. The inkjet applicator(s) 214A, 214B, 214C,214D, and 214E may include a plurality of nozzles (not shown) throughwhich the compositions 216, 218, 230, 220, and 222 are to berespectively ejected.

The inkjet applicators 214A, 214B, 214C, 214D, and 214E may respectivelydeliver drops of the first fusing agent 216, the second fusing agent218, the color agent (cyan ink composition, yellow ink composition,magenta ink composition, and black in composition) 230, the detailingagent 220, and the marking agent 222, at a resolution ranging from about300 dots per inch (DPI) to about 1200 DPI. In other examples, theapplicator(s) 214A, 214B, 214C, 214D, and 214E may deliver drops of therespective fluids 216, 218, 230, 220, and 222 at a higher or lowerresolution. The drop velocity may range from about 5 m/s to about 24 m/sand the firing frequency may range from about 1 kHz to about 100 kHz. Inone example, each drop may be in the order of about 10 picoliters (pl)per drop, although it is contemplated that a higher or lower drop sizemay be used. In some examples, inkjet applicators 214A, 214B, 214C,214D, and 214E are able to deliver variable size drops of the fluids216, 218, 230, 220, and 222, respectively.

Each of the previously described physical elements may be operativelyconnected to a controller 240 of the printing system 200. The controller240 may control the operations of the build area platform 202, the buildmaterial supply 204, the build material distributor 208, and the inkjetapplicator(s) 214A, 214B, 214C, 214D, and 214E. As an example, thecontroller 240 may control actuators (not shown) to control variousoperations of the 3D printing system 200 components. The controller 240may be a computing device, a semiconductor-based microprocessor, acentral processing unit (CPU), an application specific integratedcircuit (ASIC), and/or another hardware device. Although not shown, thecontroller 240 may be connected to the 3D printing system 200 componentsvia communication lines.

The controller 240 manipulates and transforms data, which may berepresented as physical (electronic) quantities within the printer'sregisters and memories, in order to control the physical elements tocreate the 3D part. As such, the controller 240 is depicted as being incommunication with a data store 242. The data store 242 may include datapertaining to a 3D part to be printed by the 3D printing system 200. Thedata for the selective delivery of the build material particles 206, thefirst fusing agent 216, the second fusing agent 218, the color agent230, the detailing agent 220, and the marking agent 222, may be derivedfrom a model of the 3D part to be formed. For instance, the data mayinclude the locations on each layer of build material particles 206 thatthe inkjet applicator(s) 214A, 214B, 214C, 214D, and 214E are to depositthe first fusing agent 216, the second fusing agent 218, the color agent230, the detailing agent 220, and the marking agent 222.

After the first fusing agent 216 and/or the second fusing agent 218 areselectively applied in the specific portion(s) of the build material206, the entire layer of the build material is exposed toelectromagnetic radiation. The electromagnetic radiation is emitted fromthe radiation source 244, 244′. The length of time the electromagneticradiation is applied for, or energy exposure time, may be dependent, forexample, on one or more of: characteristics of the radiation source 244,244′; characteristics of the build material particles 206; and/orcharacteristics of the first fusing agent 216 and/or second fusing agent218.

As shown in FIG. 2, the printing system 200 may also include a radiationsource 244, 244′. In some examples, the radiation source 244, 244′ maybe in a fixed position with respect to the build material platform 202.In other examples, the radiation source 244, 244′ may be positioned toexpose the layer of build material particles 206 to radiationimmediately after the first fusing agent 216 and/or the second fusingagent 218 has been applied thereto.

In the example shown in FIG. 2, the radiation source 244, 244′ isattached to the side of the inkjet applicator(s) 214A, 214B, 214C, 214D,and 214E which allows for patterning and heating in a single pass. Theradiation source 244, 244′ may emit electromagnetic radiation havingwavelengths ranging from about 400 nm to about 1 mm. As one example, theelectromagnetic radiation may range from about 400 nm to about 2 μm. Insome examples, any electromagnetic radiation source emitting in theforegoing wavelength range can be used. As another example, theelectromagnetic radiation may be blackbody radiation with a maximumintensity at a wavelength of about 1100 nm. The radiation source 244,244′ may be infrared (IR) or near-infrared light sources, such as IR ornear-IR curing lamps, IR or near-IR light emitting diodes (LED), orlasers with the desirable IR or near-IR electromagnetic wavelengths. Theradiation source 244, 244′ may be operatively connected to a lamp/laserdriver, an input/output temperature controller, and temperature sensors,which are collectively shown as radiation system components 246.

The radiation system components 246 may operate together to control theradiation source 244, 244′. The temperature recipe (e.g., radiationexposure rate) may be submitted to the input/output temperaturecontroller. During heating, the temperature sensors may sense thetemperature of the build material particles 206, and the temperaturemeasurements may be transmitted to the input/output temperaturecontroller. For example, a thermometer associated with the heated areacan provide temperature feedback. The input/output temperaturecontroller may adjust the radiation source 244, 244′ power set pointsbased on any difference between the recipe and the real-timemeasurements. These power set points are sent to the lamp/laser drivers,which transmit appropriate lamp/laser voltages to the radiation source244, 244′. This is one example of the radiation system components 246,and it is to be understood that other radiation source control systemsmay be used. For example, the controller 240 may be configured tocontrol the radiation source 244, 244′.

A layer of the build material particles 206 is applied on the build areaplatform 202. As previously described, the build material supply 204 maysupply the build material particles into a position so that they areready to be spread onto the build area platform 202, and the buildmaterial distributor 208 may spread the supplied build materialparticles 206 onto the build area platform 202. The controller 240 mayexecute control build material supply instructions to control the buildmaterial supply to appropriately position the build material particles206, and may execute control spreader instructions to control the buildmaterial distributor 208 to spread the supplied build material particlesover the build area platform to form a layer of build material particles206. After the layer is applied, the first fusing agent 216, the secondfusing agent 218, the color agent 230, and the detailing agent 220 areselectively applied on portion(s) of the build material particles 206which is then exposed to electromagnetic radiation. In some examples,electromagnetic radiation can be applied on a layer-by-layer basis.

In some examples, the first fusing agent 216 and the second fusing agent218 can enhance the absorption of the radiation in portion(s),converting the absorbed radiation to thermal energy, and promoting thetransfer of the thermal heat to the build material particles 206 incontact therewith. In an example, the first fusing agent 216 and/or thesecond fusing agent 218 can sufficiently elevate the temperature of thebuild material particles in applied portions above the melting orsoftening point of the build material particles 206, allowing fusing(e.g., sintering, binding, curing, etc.) of the build material particlesto take place. Exposure to electromagnetic radiation forms parts of oneor more layers of the final 3D object or article. It is to be understoodthat portions of the build material that do not have any fusing agentapplied thereto do not absorb enough energy to fuse. Additional layer(s)may be formed to create an example of the 3D part.

In some examples, to form additional layers, additional polymeric buildmaterial may be applied on the formed/fused layer or the layer of buildmaterial with selectively applied first and second fusing agents. Thefirst and second fusing agents can then be selectively applied on atleast a portion of the additional build material particles, according toa pattern of a cross-section for the layer which is being formed. Theapplication of additional polymeric build material particles, theselective application of the first fusing agent and/or second fusingagent, and the electromagnetic radiation exposure may be repeated apredetermined number of cycles to form the layers that will create thefinal 3D object or article. In some examples, after a first layer isformed, the first fusing agent 216, the second fusing agent 218, thecolor agent 230, and the detailing agent 220 are selectively applied onsome portions of the build material particles 206. After repetition ofthese building and application steps, a three-dimensional printed partor object is formed.

First Fusing Agent

In some examples, described herein is a first fusing agent comprising atleast one nanoparticle comprising: at least one metal oxide, whichabsorbs infrared light in a range of from about 780 nm to about 2300 nmand is shown in formula (1):

MmM′On  (1)

wherein M is an alkali metal, m is greater than 0 and less than 1, M′ isany metal, and n is greater than 0 and less than or equal to 4; andwherein the nanoparticle has a diameter of from about 0.1 nm to about500 nm.

The metal oxide can be an IR absorbing inorganic nanoparticle. In someexamples, the metal oxide can absorb infrared light in a range of fromabout 780 nm to about 2300 nm, or from about 790 nm to about 1800 nm, orfrom about 800 nm to about 1500 nm, or from about 810 nm to about 1200nm, or from about 820 nm to about 1100 nm, or from about 830 nm to about1000 nm.

In some examples, the metal oxide can be defined as shown in formula (1)below:

MmM′On  (1).

M in formula (1) above can be an alkali metal. In some examples, M canbe lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs),or mixtures thereof. In some examples, M can be cesium (Cs).

m in formula (1) above can be greater than 0 and less than 1. In someexamples, m can be 0.33.

M′ in formula (1) above can be any metal. In some examples, M′ can betungsten (W), molybdenum (Mb), tantalum (Ta), hafnium (Hf), cerium (Ce),lanthanum (La), or mixtures thereof. In some examples, M′ can betungsten (W).

n in formula (1) above can be greater than 0 and less than or equal to4. In some examples, n in formula (1) above can be greater than 0 andless than or equal to 3.

In some examples, the nanoparticle can have a diameter of from about 0.1nm to about 500 nm, or from about 0.5 nm to about 400 nm, or from about0.6 nm to about 300 nm, or from about 0.7 nm to about 250 nm, or fromabout 0.8 nm to about 200 nm, or from about 0.9 nm to about 150 nm, orfrom about 1 nm to about 100 nm, or from about 1 nm to about 90 nm, orfrom about 1 nm to about 80 nm, or from about 1 nm to about 70 nm, orfrom about 1 nm to about 60 nm, or from about 2 nm to about 50 nm, orfrom about 3 nm to about 40 nm, or from about 4 nm to about 40 nm.

In some examples, the metal oxide particles can have a diameter of fromabout 0.01 nm to about 400 nm, or from about 0.1 nm to about 350 nm, orfrom about 0.5 nm to about 300 nm, or from about 0.7 nm to about 250 nm,or from about 0.8 nm to about 200 nm, or from about 0.9 nm to about 150nm, or from about 1 nm to about 100 nm, or from about 1 nm to about 90nm, or from about 1 nm to about 80 nm, or from about 1 nm to about 70nm, or from about 1 nm to about 60 nm, or from about 2 nm to about 50nm, or from about 3 nm to about 40 nm, or from about 3 nm to about 30nm, or from about 3 to about 20 nm, or from about 3 to about 10 nm.

In some examples, a first fusing agent used in three-dimensionalprinting can comprise: (A) water; (B) at least one co-solvent; and (C)at least one nanoparticle comprising: at least one metal oxide, whichabsorbs infrared light in a range of from about 780 nm to about 2300 nmand is shown in formula (1):

MmM′On  (1)

wherein M is an alkali metal, m is greater than 0 and less than 1, M′ isany metal, and n is greater than 0 and less than or equal to 4; and thenanoparticle has a diameter of from about 0.1 nm to about 500 nm.

In some examples, the first fusing agent can further include otheradditives including at least one buffer solution, at least onesurfactant, at least one dispersant, at least one biocide, at least onestabilizer, at least one anti-kogation agent, at least one complexingagent, and/or combinations thereof.

In some examples, the at least one nanoparticle is present in an amountof from about 1 wt % to about 20 wt % based on the total weight of thefirst fusing agent.

In some examples, the first fusing agent is added in thethree-dimensional printing composition in an amount of from about 1 wt %to about 30 wt % based on the total weight of the three-dimensionalprinting composition, or from about 5 wt % to about 25 wt %, or fromabout 8 wt % to about 20 wt %, or less than about 35 wt %, or less thanabout 25 wt %, or less than about 20 wt %, or less than about 15 wt %,or less than about 10 wt %, or at least about 1 wt %, or at least about3 wt %, or at least about 5 wt %, or at least about 8 wt %, or at leastabout 10 wt %, or at least about 15 wt %, or at least about 20 wt %, orat least about 30 wt %, or at least about 35 wt %.

In some examples, the nanoparticles in the first fusing agent arepresent in an amount of at least about 1 wt % based on the total weightof first fusing agent, or at least about 3 wt %, or at least about 5 wt%, or at least about 7 wt %, or at least about 10 wt %, or at least 15wt %, or less than about 20 wt %, or less than about 15 wt %, or lessthan about 12 wt %, or less than about 10 wt %, or less than about 8 wt%, or less than about 7 wt %, or less than about 6 wt %, or less thanabout 5 wt %.

In some examples, in formula (1) shown above, M is cesium (Cs), m is0.33, M′ is tungsten (W), and n is greater than 0 and less than or equalto 3.

In some examples, the metal oxide nanoparticles are plasmonic resonanceabsorbers, having absorption at wavelengths ranging from 800 nm to 4000nm and transparency at wavelengths ranging from 400 nm to 780 nm. Asused herein “absorption” means that at least 80% of radiation havingwavelengths ranging from 800 nm to 4000 nm is absorbed. Also usedherein, “transparency” means that 40% or less of radiation havingwavelengths ranging from 400 nm to 780 nm is absorbed. This absorptionand transparency allows the first fusing agent to absorb enoughradiation to fuse the build material in contact therewith while causingthe 3D part to be white or slightly colored. The metal oxidenanoparticles can be considered as the first fusing agent per se, i.e.,the specific compound that provides the specific properties to the firstfusing agent composition 216.

In some examples, the metal oxide nanoparticles that are part of thefirst fusing agent composition, have the formula (1) MmM′On wherein M isan alkali metal, m is greater than 0 and less than 1, M′ is any metal,and n is greater than 0 and less than or equal to 4. The metal oxidenanoparticles are a dispersion in the first fusing agent composition. Asused herein, the term “dispersion” can refer to a two-phase system whereone phase consists of finely divided metal oxide particle distributedthroughout a bulk substance, i.e., liquid vehicle. The metal oxidenanoparticles are the dispersed or internal phase and the bulk substanceis the continuous or external phase (liquid vehicle). As disclosedherein, the liquid medium is an aqueous liquid medium, i.e., comprisingwater and in some examples water and at least one co-solvent.

In some examples, the metal oxide nanoparticles have formula (1): MmM′On(1) wherein M is an alkali metal, m is greater than 0 and less than 1,M′ is any metal, and n is greater than 0 and less than or equal to 4. Asper formula (1), M is an alkali metal, and can be lithium (Li), sodium(Na), potassium (K), rubidium (Rb), cesium (Cs), or mixtures thereof.Indeed, without being linked by any theory, it is believed that suchcompound possesses a satisfactory absorption of NIR light (having awavelength between about 750 nm to about 1400 nm) while retaining a hightransmittance of visible light (having a wavelength between about 380 nmto about 750 nm).

In some examples, the nanoparticles absorb infrared light in a range offrom about 750 nm to about 2300 nm. In some other examples, thenanoparticles absorb infrared light in a range of from about 780 nm toabout 1400 nm. In yet some other examples, the nanoparticles absorbinfrared light in a range of from about 780 nm to about 2300 nm. Themetal oxide nanoparticles can also absorb infrared light in a range offrom about 780 nm to about 2300 nm, or from about 790 nm to about 1800nm, or from about 800 nm to about 1500 nm, or from about 810 nm to about1200 nm, or from about 820 nm to about 1100 nm, or from about 830 nm toabout 1000 nm. The metal oxide can be an IR absorbing inorganicnanoparticle.

The metal oxide nanoparticles present in the first fusing agent, havethe formula (1) MmM′On. In the formula (1), M is an alkali metal. Insome examples, M is lithium (Li), sodium (Na), potassium (K), rubidium(Rb), cesium (Cs), or mixtures thereof. In some other examples, M iscesium (Cs). In the formula (1), M′ is any metal. In some examples, M′is tungsten (W), molybdenum (Mb), tantalum (Ta), hafnium (Hf), cerium(Ce), lanthanum (La), or mixtures thereof. In some other examples, M′ istungsten (W). In the formula (1), m is greater than 0 and less than 1.In some examples, m can be 0.33. In the formula (1), n is greater than 0and less than or equal to 4. In some examples, n can be greater than 0and less than or equal to 3. In some examples, the nanoparticles of thepresent disclosure have the formula (1) MmM′On, wherein M is tungsten(W), n is 3 and M is lithium (Li), sodium (Na), potassium (K), rubidium(Rb), cesium (Cs), or mixtures thereof. The nanoparticles are thustungsten bronze nanoparticles having the formula MmWO₃.

In some other examples, the metal oxide nanoparticles are cesiumtungsten nanoparticles having the formula (1) MmM′On, wherein M iscesium (Cs), m is 0.33, M′ is tungsten (W), and n is greater than 0 andless than or equal to 3. In an example, the metal oxide nanoparticle isa cesium tungsten oxide nanoparticles having a general formula ofCsxWO₃, where 0<x<1. The cesium tungsten oxide nanoparticles may givethe dispersion a light blue color. The strength of the color may depend,at least in part, on the amount of the cesium tungsten oxidenanoparticles in the dispersion.

In some examples, the metal oxide particles can have a diameter of fromabout 0.01 nm to about 400 nm, or from about 0.1 nm to about 350 nm, orfrom about 0.5 nm to about 300 nm, or from about 0.7 nm to about 250 nm,or from about 0.8 nm to about 200 nm, or from about 0.9 nm to about 150nm, or from about 1 nm to about 100 nm, or from about 1 nm to about 90nm, or from about 1 nm to about 80 nm, or from about 1 nm to about 70nm, or from about 1 nm to about 60 nm, or from about 2 nm to about 50nm, or from about 3 nm to about 40 nm, or from about 3 nm to about 30nm, or from about 3 to about 20 nm, or from about 3 to about 10 nm. In amore specific example, the average particle size (e.g., volume-weightedmean diameter) of the metal oxide nanoparticles may range from about 1nm to about 40 nm. In some examples, the average particle size of themetal oxide nanoparticles may range from about 1 nm to about 15 nm orfrom about 1 nm to about 10 nm. The upper end of the particle size range(e.g., from about 30 nm to about 40 nm) may be less desirable, as theseparticles may be more difficult to stabilize. In some examples, themetal oxide nanoparticles may be present in first fusing agentcomposition in an amount ranging from about 1 wt % to about 20 wt %(based on the total wt % of the first fusing agent composition).

The first fusing agent composition comprising metal oxide nanoparticles,also includes the zwitterionic stabilizer. The zwitterionic stabilizermay improve the stabilization of the dispersion. While the zwitterionicstabilizer has an overall neutral charge, at least one area of themolecule has a positive charge (e.g., amino groups) and at least oneother area of the molecule has a negative charge. The metal oxidenanoparticles may have a slight negative charge. The zwitterionicstabilizer molecules may orient around the slightly negative metal oxidenanoparticles with the positive area of the zwitterionic stabilizermolecules closest to the metal oxide nanoparticles and the negative areaof the zwitterionic stabilizer molecules furthest away from the metaloxide nanoparticles. Then the negative charge of the negative area ofthe zwitterionic stabilizer molecules may repel metal oxidenanoparticles from each other. The zwitterionic stabilizer molecules mayform a protective layer around the metal oxide nanoparticles, andprevent them from coming into direct contact with each other and/orincrease the distance between the particle surfaces (e.g., by a distanceranging from about 1 nm to about 2 nm). Thus, the zwitterionicstabilizer may prevent the metal oxide nanoparticles from agglomeratingand/or settling in the dispersion. Examples of suitable zwitterionicstabilizers include C₂ to C₄ betaines, C₂ to C₄ amino-carboxylic acidshaving a solubility of at least 10 g in 100 g of water, taurine, andcombinations thereof. Examples of the C₂ to C₄ amino-carboxylic acidsinclude beta-alanine, gamma-aminobutyric acid, glycine, and combinationsthereof.

The zwitterionic stabilizer may be present, in the first fusing agentcomposition, in an amount ranging from about 2 wt % to about 35 wt %(based on the total wt % of the first fusing agent composition). Whenthe zwitterionic stabilizer is the C₂ to C₄ betaine, the C₂ to C₄betaine may be present in an amount ranging from about 4 wt % to about35 wt % of a total wt % of the first fusing agent composition. When thezwitterionic stabilizer is the C₂ to C₄ amino-carboxylic acid, the C₂ toC₄ amino-carboxylic acid may be present in an amount ranging from about2 wt % to about 20 wt % of a total wt % of the first fusing agentcomposition. When the zwitterionic stabilizer is taurine, taurine may bepresent in an amount ranging from about 2 wt % to about 35 wt % of atotal wt % of the first fusing agent composition. The zwitterionicstabilizer may be added to the metal oxide nanoparticles and waterbefore, during, or after milling of the nanoparticles in the water toform the dispersion that would be part of the first fusing agentcomposition.

In an example, the first fusing agent composition disclosed hereinincludes the metal oxide nanoparticles, the zwitterionic stabilizer, asurfactant, and a liquid vehicle. In another example, the first fusingagent composition includes the metal oxide nanoparticles, thezwitterionic stabilizer, a co-solvent, a surfactant, and a balance ofwater. In yet other examples, the first fusing agent composition mayinclude additional components, such as an additive. As used herein, theterms “liquid vehicle” and “vehicle” may refer to the liquid fluid inwhich the metal oxide nanoparticles and the zwitterionic stabilizer areplaced to form the first fusing agent composition. A wide variety ofliquid vehicles may be used with the first fusing agent composition setof the present disclosure. The vehicle may include water alone or incombination with a variety of additional components. Examples of theseadditional components may include co-solvent, surfactant, antimicrobialagent, anti-kogation agent, and/or a chelating agent.

The liquid vehicle of the first fusing agent composition may alsoinclude surfactants. The surfactant may be present in an amount rangingfrom about 0.1 wt % to about 4 wt % (based on the total wt % of thefirst fusing agent composition). Examples of suitable surfactants arenon-ionic surfactants. Some specific examples include aself-emulsifiable, nonionic wetting agent based on acetylenic diolchemistry (e.g., Surfynol® SEF from Air Products and Chemicals, Inc.), anonionic fluorosurfactant (e.g., Capstone fluorosurfactants from DuPont,previously known as Zonyl FSO), and combinations thereof. In otherexamples, the surfactant is an ethoxylated low-foam wetting agent (e.g.,Surfynol® 440 or Surfynol® CT-111 from Air Products and Chemical Inc.)or an ethoxylated wetting agent and molecular defoamer (e.g., Surfynol®420 from Air Products and Chemical Inc.). Still other suitablesurfactants include non-ionic wetting agents and molecular defoamers(e.g., Surfynol® 104E from Air Products and Chemical Inc.), orwater-soluble, non-ionic surfactants (e.g., Tergitol® TMN-6, Tergitol®15S7, and Tergitol® 15S9 from The Dow Chemical Company). In someexamples, an anionic surfactant may be used in combination with thenon-ionic surfactant. One suitable anionic surfactant is analkyldiphenyloxide disulfonate (e.g., Dowfax® 8390 and Dowfax® 2A1 fromThe Dow Chemical Company). In some examples, it may be desirable toutilize a surfactant having a hydrophilic-lipophilic balance (HLB) lessthan 10.

The vehicle may include co-solvent(s). Some examples of the co-solventthat may be added to the vehicle include1-(2-hydroxyethyl)-2-pyrollidinone, 2-pyrrolidinone,2-methyl-1,3-propanediol, 1,5-pentanediol, triethylene glycol,tetraethylene glycol, 1,6-hexanediol, tripropylene glycol methyl ether,ethoxylated glycerol-1 (LEG-1), and combinations thereof. Whether asingle co-solvent is used or a combination of co-solvents is used, thetotal amount of co-solvent(s) in the first fusing agent composition mayrange from about 2 wt % to about 80 wt % with respect to the total wt %of the first fusing agent composition.

In some examples, the liquid vehicle may also include one or moreadditives. The additive may be an anti-kogation agent, a chelatingagent, an antimicrobial agent, or a combination thereof. While theamount of the additive may vary depending upon the type of additive,generally the additive may be present in the first fusing agentcomposition in an amount ranging from about 0.001 wt % to about 20 wt %(based on the total wt % of the first fusing agent composition).

An anti-kogation agent may be included in the first fusing agentcomposition. Kogation refers to the deposit of dried first fusing agentcomposition components on a heating element of a thermal inkjetprinthead. Anti-kogation agent(s) is/are included to assist inpreventing the buildup of kogation. Examples of suitable anti-kogationagents include oleth-3-phosphate (e.g., commercially available asCrodafos®O3A or Crodafos®N-3 acid from Croda), or a combination ofoleth-3-phosphate and a low molecular weight (e.g., <5,000) polyacrylicacid polymer. Whether a single anti-kogation agent is used or acombination of anti-kogation agents is used, the total amount ofanti-kogation agent(s) in the first fusing agent composition may rangefrom about 0.1 wt % to about 0.2 wt % (based on the total wt % of thefirst fusing agent composition).

The liquid vehicle may also include a chelating agent. The chelatingagent may be included in the first fusing agent composition to eliminatethe deleterious effects of heavy metal impurities. Examples of suitablechelating agents include disodium ethylene-diaminetetraacetic acid(EDTA-Na), ethylene diamine tetra acetic acid (EDTA), andmethyl-glycinediacetic acid (e.g., Trilon® M from BASF Corp.). Whether asingle chelating agent is used or a combination of chelating agents isused, the total amount of chelating agent(s) in the first fusing agentcomposition may range from 0 wt % to about 2 wt % based on the total wt% of the first fusing agent composition.

The liquid vehicle may also include antimicrobial agents. Suitableantimicrobial agents include biocides and fungicides. Exampleantimicrobial agents may include the Nuosept® (Ashland Inc.), Vancide®(R.T. Vanderbilt Co.), Acticide® B20 and Acticide® M20 (Thor Chemicals),and combinations thereof. In an example, the first fusing agentcomposition may include a total amount of antimicrobial agents thatranges from about 0.1 wt % to about 1 wt % (based on the total wt % ofthe first fusing agent composition). In some examples disclosed herein,the vehicle of the first fusing agent composition may also includeadditional dispersants (e.g., a low molecular weight (e.g., <5,000)polyacrylic acid polymer, such as Carbosperse®K-7028 Polyacrylate fromLubrizol), preservatives, jettability additives, and the like.

The first fusing agent (or first fusing agent (LTFA)) 216 can be anaqueous jettable composition that can include metal oxide nanoparticles;a zwitterionic stabilizer; a surfactant; and an aqueous vehicle. Thefirst fusing agent composition comprises metal oxide nanoparticle thatmight give the fusing agent a transparent or translucent or a light bluecolor. The first fusing agent is different from the second fusing agentdue to its chemical composition and also due to its final color. Thefirst fusing agent composition 216 comprises metal oxide nanoparticlesthat act as a plasmonic resonance absorber. The metal oxidenanoparticles (plasmonic resonance absorber) allows the first fusingagent composition to absorb radiation at wavelengths ranging from 800 nmto 4000 nm, which enables the first fusing agent composition to convertenough radiation to thermal energy so that the build material particlesfuse. The plasmonic resonance absorber also allows the first fusingagent composition to have transparency at wavelengths ranging from 400nm to 780 nm, which enables the 3D part or layer form with agent to bewhite or slightly colored. The term “low tint” is used herein to definethe fusing agent by opposition to the “core” fusing agent. The ““lowtint” will provide to the parts containing it, a “low tint” color inrelation with its absorption range (nearly transparency at wavelengthsranging from 400 nm to 780 nm). On the opposite, the second fusing agentsince its contains a radiation absorbing agent, will provide to theparts containing it, a dark color in relation with the absorption of thecolorant contained in it. The colorant can be any infrared lightabsorbing colorant (and can be black reflecting thus a black color).

Second Fusing Agent

In some examples, the second fusing agent comprises a near infraredabsorbing compound.

In some examples, the near infrared absorbing compound is selected fromthe group consisting of carbon black, oxonol, squarylium,chalcogenopyrylarylidene, bis(chalcogenopyrylo)polymethine,bis(aminoaryl)polymethine, merocyanine, trinuclear cyanine,indene-crosslinked polymethine, oxyindolidine, iron complexes, quinoids,nickel-dithiolene complex, cyanine dyes, and combinations thereof.

The cyanine dyes can be selected from the group consisting ofcarbocyanine, azacarbocyanine, hemicyanine, styryl, diazacarbocyanine,triazacarbocyanine, diazahemicyanine, polymethinecyanine,azapolymethinecyanine, holopolar, indocyanine, diazahemicyanine dyes,and combinations thereof.

In some examples, the near infrared absorbing compound is carbon black.

In some examples, the second fusing agent further comprises: at leastone co-solvent; at least one surfactant; at least one anti-kogationagent; at least one chelating agent; at least one buffer solution; atleast one biocide; and water.

In some examples, the second fusing agent is added in thethree-dimensional printing composition in an amount of from about 1 wt %to about 30 wt % based on the total weight of the three-dimensionalprinting composition, or from about 5 wt % to about 25 wt %, or fromabout 8 wt % to about 20 wt %, or less than about 35 wt %, or less thanabout 25 wt %, or less than about 20 wt %, or less than about 15 wt %,or less than about 10 wt %, or at least about 1 wt %, or at least about3 wt %, or at least about 5 wt %, or at least about 8 wt %, or at leastabout 10 wt %, or at least about 15 wt %, or at least about 20 wt %, orat least about 30 wt %, or at least about 35 wt %.

In some examples, the near infrared absorbing compound in the secondfusing agent is present in an amount of at least about 1 wt % based onthe total weight of second fusing agent, or at least about 3 wt %, or atleast about 5 wt %, or at least about 7 wt %, or at least about 10 wt %,or at least 15 wt %, or less than about 20 wt %, or less than about 15wt %, or less than about 12 wt %, or less than about 10 wt %, or lessthan about 8 wt %, or less than about 7 wt %, or less than about 6 wt %,or less than about 5 wt %.

The second fusing agent 218 is a jettable composition. The second fusingagent composition is an aqueous jettable composition that includesradiation absorbing agent (i.e., an active material) and an aqueousvehicle. Examples of the second fusing agent 218 are water-baseddispersions including a radiation absorbing agent (i.e., an activematerial). The amount of the active material in the second fusing agentmay depend upon how absorbing the active material is. In an example, thesecond fusing agent may include the active material and may be appliedin an amount sufficient to include at least 0.01 wt % of the activematerial in the 3D part layer that is formed with the second fusingagent. Even this low amount can produce a black colored part layer. Thesecond fusing agents tend to have significant absorption (e.g., 80%) inthe visible region (400 nm-780 nm). This absorption generates heatsuitable for fusing during 3D printing, which leads to 3D parts havingmechanical integrity and relatively uniform mechanical properties (e.g.,strength, elongation at break, etc.). The radiation absorbing agent is adispersion of material in the aqueous vehicle. As used herein, the term“dispersion” refers to a two-phases system where one phase consists offinely divided radiation absorbing agent distributed throughout a bulksubstance, i.e. liquid vehicle. The radiation absorbing agent is thedispersed or internal phase and the bulk substance is the continuous orexternal phase (liquid vehicle). As disclosed herein the liquid mediumis an aqueous liquid medium, i.e. comprising water.

The active material, or radiation absorbing agent, may be any infraredlight absorbing colorant that is black. In an example, the activematerial, or radiation absorbing agent is a near infrared absorbingcompound. Any near infrared black colorants may be used. In someexamples, the second fusing agent includes near infrared absorbingcompound and an aqueous vehicle.

In some examples, the active material, or radiation absorbing agent, isa carbon back pigment or near infrared absorbing dyes. In some otherexamples, the active material, or radiation absorbing agent, is a carbonback pigment; and the second fusing agent composition may be an inkformulation including carbon black as the active material. Examples ofthis ink formulation are commercially known as CM997A, 5206458, C18928,C93848, C93808, or the like, all of which are available from HP Inc. Inyet some other examples, the second fusing agent may be an inkformulation including near infrared absorbing dyes as the activematerial.

The second fusing agent composition is an aqueous formulation (i.e.,includes a balance of water) that may also include any of the previouslylisted co-solvents, non-ionic surfactants, biocides, and/oranti-kogation agents. The second fusing agent composition includes anaqueous vehicle as defined above. In an example of the second fusingagent composition, the co-solvents are present in an amount ranging fromabout 1 wt % to about 60 wt % of the total wt % of the second fusingagent composition, the non-ionic surfactants are present in an amountranging from about 0.5 wt. % to about 1.5 wt. % based on the total wt. %of the second fusing agent composition, the biocides are present in anamount ranging from about 0.1 wt. % to about 5 wt. % based on the totalwt. % of the second fusing agent composition, and/or the anti-kogationagents are present in an amount ranging from about 0.1 wt. % to about 5wt. % based on the total wt. % of the second fusing agent composition.Some examples of the second fusing agent composition may also include apH adjuster, which is used to control the pH of the agent. From 0 wt %to about 2 wt % (of the total wt % of the second fusing agent) of the pHadjuster, for example, can be used.

Color Agent

The color agent 230 (also referred to herein as the colored inkcomposition) can include a colorant, a dispersant/dispersing additive, aco-solvent, and water. The colored ink composition 230 is a water-basedinkjet composition. In some instances, the colored ink compositionincludes these components and no other components. In other instances,the colored ink composition may further include an anti-kogation agent,a biocide, a binder, and combinations thereof.

The colorant of the colored ink composition is a pigment and/or dyehaving a color other than white. Examples of the other colors includecyan, magenta, yellow, black, etc. In some instances, the colorant ofthe colored ink may also be transparent to infrared wavelengths.Examples of IR transparent colorants include acid yellow 23 (AY 23),AY17, acid red 52 (AR 52), AR 289, and reactive red 180 (RR 180). Inother instances, the colorant of the colored ink composition may not becompletely transparent to infrared wavelengths, but does not absorbenough radiation to sufficiently heat the build material particles incontact therewith. For example, the colorant of the colored inkcomposition may absorb some visible wavelengths and some IR wavelengths.Some examples of these colorants include cyan colorants, such as directblue 199 (DB 199) and pigment blue 15:3 (PB 15:3).

The colored ink composition also includes the dispersing additive, whichhelps to uniformly distribute the colorant throughout the colored inkcomposition and aid in the wetting of the ink 230 onto the buildmaterial particles. Any of the dispersing additives discussed herein forthe fusing agent may be used in the colored ink composition. Thedispersing additive may be present in the colored ink composition in asimilar amount as the colorant.

In addition to the non-white colorant and the dispersing additives, thecolored ink composition may include similar components as the fusingagent (e.g., co-solvent(s), anti-kogation agent(s), biocide(s), water,etc.). The colored ink composition may also include a binder, such as anacrylic latex binder, which may be a copolymer of any two or more ofstyrene, acrylic acid, methacrylic acid, methyl methacrylate, ethylmethacrylate, and butyl methacrylate. Some examples of the colored inkcomposition may also include other additives, such as a humectant andlubricant (e.g., Liponic EG-1 (LEG-1) from Lipo Chemicals), a chelatingagent (e.g., disodium ethylene diamine-tetraacetic acid (EDTA-Na)),and/or a buffer.

An example of the pigment based colored ink composition may include fromabout 1 wt % to about 10 wt % of pigment(s), from about 10 wt % to about30 wt % of co-solvent(s), from about 1 wt % to about 10 wt % ofdispersing additive(s), from 0.01 wt % to about 1 wt % of anti-kogationagent(s), from about 0.1 wt % to about 5 wt % of binder(s), from about0.05 wt % to about 0.1 wt % biocide(s), and a balance of water. Anexample of the dye based colored ink composition may include from about1 wt % to about 7 wt % of dye(s), from about 10 wt % to about 30 wt % ofco-solvent(s), from about 1 wt % to about 7 wt % of dispersingadditive(s), from 0.05 wt % to about 0.1 wt % of chelating agent(s),from about 0.005 wt % to about 0.2 wt % of buffer(s), from about 0.05 wt% to about 0.1 wt % biocide(s), and a balance of water.

In some examples, the colored ink composition includes cyan ink agent(C), yellow ink agent (Y), magenta ink agent (M), and black ink agent(K). In some examples, additional ink compositions may be used inaddition to the CYMK colored ink composition. The color agents are alsoreferred herein as color compositions—e.g., cyan ink composition.

The colorant(s) in the colored ink composition(s) described herein caninclude inorganic pigments, organic pigments, dyes, and combinationsthereof.

The pigment may be any color, including, as examples, a cyan pigment, amagenta pigment, a yellow pigment, a black pigment, a violet pigment, agreen pigment, a brown pigment, an orange pigment, a purple pigment, awhite pigment, a metallic pigment (e.g., a gold pigment, a bronzepigment, a silver pigment, or a bronze pigment), a pearlescent pigment,or combinations thereof.

In some examples, the colored ink composition includes cyan ink, yellowink, magenta ink, and black ink.

Examples of suitable yellow organic pigments include C.I. Pigment Yellow1, C.I. Pigment Yellow 2, C.I. Pigment Yellow 3, C.I. Pigment Yellow 4,C.I. Pigment Yellow 5, C.I. Pigment Yellow 6, C.I. Pigment Yellow 7,C.I. Pigment Yellow 10, C.I. Pigment Yellow 11, C.I. Pigment Yellow 12,C.I. Pigment Yellow 13, C.I. Pigment Yellow 14, C.I. Pigment Yellow 16,C.I. Pigment Yellow 17, C.I. Pigment Yellow 24, C.I. Pigment Yellow 34,C.I. Pigment Yellow 35, C.I. Pigment Yellow 37, C.I. Pigment Yellow 53,C.I. Pigment Yellow 55, C.I. Pigment Yellow 65, C.I. Pigment Yellow 73,C.I. Pigment Yellow 74, C.I. Pigment Yellow 75, C.I. Pigment Yellow 77,C.I. Pigment Yellow 81, C.I. Pigment Yellow 83, C.I. Pigment Yellow 93,C.I. Pigment Yellow 94, C.I. Pigment Yellow 95, C.I. Pigment Yellow 97,C.I. Pigment Yellow 98, C.I. Pigment Yellow 99, C.I. Pigment Yellow 108,C.I. Pigment Yellow 109, C.I. Pigment Yellow 110, C.I. Pigment Yellow113, C.I. Pigment Yellow 114, C.I. Pigment Yellow 117, C.I. PigmentYellow 120, C.I. Pigment Yellow 122, C.I. Pigment Yellow 124, C.I.Pigment Yellow 128, C.I. Pigment Yellow 129, C.I. Pigment Yellow 133,C.I. Pigment Yellow 138, C.I. Pigment Yellow 139, C.I. Pigment Yellow147, C.I. Pigment Yellow 151, C.I. Pigment Yellow 153, C.I. PigmentYellow 154, C.I. Pigment Yellow 167, C.I. Pigment Yellow 172, C.I.Pigment Yellow 180, and C.I. Pigment Yellow 185.

Examples of suitable blue or cyan organic pigments include C.I. PigmentBlue 1, C.I. Pigment Blue 2, C.I. Pigment Blue 3, C.I. Pigment Blue 15,Pigment Blue 15:3, C.I. Pigment Blue 15:34, C.I. Pigment Blue 15:4, C.I.Pigment Blue 16, C.I. Pigment Blue 18, C.I. Pigment Blue 22, C.I.Pigment Blue 25, C.I. Pigment Blue 60, C.I. Pigment Blue 65, C.I.Pigment Blue 66, C.I. Vat Blue 4, and C.I. Vat Blue 60.

Examples of suitable magenta, red, or violet organic pigments includeC.I. Pigment Red 1, C.I. Pigment Red 2, C.I. Pigment Red 3, C.I. PigmentRed 4, C.I. Pigment Red 5, C.I. Pigment Red 6, C.I. Pigment Red 7, C.I.Pigment Red 8, C.I. Pigment Red 9, C.I. Pigment Red 10, C.I. Pigment Red11, C.I. Pigment Red 12, C.I. Pigment Red 14, C.I. Pigment Red 15, C.I.Pigment Red 16, C.I. Pigment Red 17, C.I. Pigment Red 18, C.I. PigmentRed 19, C.I. Pigment Red 21, C.I. Pigment Red 22, C.I. Pigment Red 23,C.I. Pigment Red 30, C.I. Pigment Red 31, C.I. Pigment Red 32, C.I.Pigment Red 37, C.I. Pigment Red 38, C.I. Pigment Red 40, C.I. PigmentRed 41, C.I. Pigment Red 42, C.I. Pigment Red 48(Ca), C.I. Pigment Red48(Mn), C.I. Pigment Red 57(Ca), C.I. Pigment Red 57:1, C.I. Pigment Red88, C.I. Pigment Red 112, C.I. Pigment Red 114, C.I. Pigment Red 122,C.I. Pigment Red 123, C.I. Pigment Red 144, C.I. Pigment Red 146, C.I.Pigment Red 149, C.I. Pigment Red 150, C.I. Pigment Red 166, C.I.Pigment Red 168, C.I. Pigment Red 170, C.I. Pigment Red 171, C.I.Pigment Red 175, C.I. Pigment Red 176, C.I. Pigment Red 177, C.I.Pigment Red 178, C.I. Pigment Red 179, C.I. Pigment Red 184, C.I.Pigment Red 185, C.I. Pigment Red 187, C.I. Pigment Red 202, C.I.Pigment Red 209, C.I. Pigment Red 219, C.I. Pigment Red 224, C.I.Pigment Red 245, C.I. Pigment Red 286, C.I. Pigment Violet 19, C.I.Pigment Violet 23, C.I. Pigment Violet 32, C.I. Pigment Violet 33, C.I.Pigment Violet 36, C.I. Pigment Violet 38, C.I. Pigment Violet 43, andC.I. Pigment Violet 50.

Examples of carbon black pigments include those manufactured byMitsubishi Chemical Corporation, Japan (such as, e.g., carbon black No.2300, No. 900, MCF88, No. 33, No. 40, No. 45, No. 52, MA7, MA8, MA100,and No. 2200B); various carbon black pigments of the RAVEN® seriesmanufactured by Columbian Chemicals Company, Marietta, Ga., (such as,e.g., RAVEN® 5750, RAVEN® 5250, RAVEN® 5000, RAVEN® 3500, RAVEN® 1255,and RAVEN®700); various carbon black pigments of the BLACK PEARLS®series, REGAL® series, the MOGUL® series, or the MONARCH® seriesmanufactured by Cabot Corporation, Boston, Mass., (such as, e.g., BLACKPEARLS® 880 Carbon Black, REGAL® 400R, REGAL® 330R, and REGAL® 660R);and various black pigments manufactured by Evonik Degussa Corporation,Parsippany, N.J., (such as, e.g., Color Black FW1, Color Black FW2,Color Black FW2V, Color Black FW18, Color Black FW200, Color Black S150,Color Black S160, Color Black S170, PRINTEX® 35, PRINTEX® U, PRINTEX® V,PRINTEX® 140U, Special Black 5, Special Black 4A, and Special Black 4).An example of an organic black pigment includes aniline black, such asC.I. Pigment Black 1.

Some examples of green organic pigments include C.I. Pigment Green 1,C.I. Pigment Green 2, C.I. Pigment Green 4, C.I. Pigment Green 7, C.I.Pigment Green 8, C.I. Pigment Green 10, C.I. Pigment Green 36, and C.I.Pigment Green 45.

Examples of brown organic pigments include C.I. Pigment Brown 1, C.I.Pigment Brown 5, C.I. Pigment Brown 22, C.I. Pigment Brown 23, C.I.Pigment Brown 25, C.I. Pigment Brown 41, and C.I. Pigment Brown 42.

Some examples of orange organic pigments include C.I. Pigment Orange 1,C.I. Pigment Orange 2, C.I. Pigment Orange 5, C.I. Pigment Orange 7,C.I. Pigment Orange 13, C.I. Pigment Orange 15, C.I. Pigment Orange 16,C.I. Pigment Orange 17, C.I. Pigment Orange 19, C.I. Pigment Orange 24,C.I. Pigment Orange 34, C.I. Pigment Orange 36, C.I. Pigment Orange 38,C.I. Pigment Orange 40, C.I. Pigment Orange 43, and C.I. Pigment Orange66.

A suitable metallic pigment includes a metal chosen from gold, silver,platinum, nickel, chromium, tin, zinc, indium, titanium, copper,aluminum, and alloys of any of these metals. These metals may be usedalone or in combination with two or more metals or metal alloys. Someexamples of metallic pigments include STANDART® R0100, STANDART® R0200,and DORADO® gold-bronze pigments (available from Eckart Effect Pigments,Wesel, Germany).

In some examples, the above pigments can be used alone or in anycombination with one another.

The total amount of the colorant(s) in the colored ink composition(s)ranges from about 0.1 wt % to about 15 wt % based on the total weight ofthe colored ink composition(s). In some examples, the total amount ofthe colorant(s) in the colored ink composition(s) ranges from about 1 wt% to about 8 wt % based on the total weight of the colored inkcomposition(s).

In some examples, the average particle size of these colorant(s) mayrange from about 80 nm to about 400 nm.

In some examples, the above-described colorant(s) can be dispersed intoa polymeric dispersion. In some examples, the colorant(s) (e.g.,pigment(s)) can be dispersed in a dispersion comprising a styreneacrylic polymer. The polymeric dispersion comprising a styrene acrylicpolymer can assist in dispersing the pigment in a solvent system.

A variety of styrene acrylic polymers can be used for the pigmentdispersion. Some non-limiting commercial examples of useful styreneacrylic polymers are sold under the trade names JONCRYL® (S.C. JohnsonCo.), UCARM (Dow Chemical Co.), JONREZ® (MeadWestvaco Corp.), andVANCRYL® (Air Products and Chemicals, Inc.).

In further detail, the styrene acrylic polymer can be formulated with avariety of monomers, such as hydrophilic monomers, hydrophobic monomers,or combinations thereof. Non-limiting examples of hydrophilic monomersthat can be co-polymerized together to form the styrene acrylic polymerinclude acrylic acid, methacrylic acid, ethacrylic acid, dimethylacrylicacid, maleic anhydride, maleic acid, vinylsulfonate, cyanoacrylic acid,vinylacetic acid, allylacetic acid, ethylidineacetic acid,propylidineacetic acid, crotonoic acid, fumaric acid, itaconic acid,sorbic acid, angelic acid, cinnamic acid, styrylacrylic acid, citraconicacid, glutaconic acid, aconitic acid, phenylacrylic acid,acryloxypropionic acid, aconitic acid, phenylacrylic acid,acryloxypropionic acid, vinylbenzoic acid, N-vinylsuccinamidic acid,mesaconic acid, methacroylalanine, acryloylhydroxyglycine, sulfoethylmethacrylic acid, sulfopropyl acrylic acid, styrene sulfonic acid,sulfoethylacrylic acid, 2-methacryloyloxymethane-1-sulfonic acid,3-methacryoyloxypropane-1-sulfonic acid, 3-(vinyloxy)propane-1-sulfonicacid, ethylenesulfonic acid, vinyl sulfuric acid, 4-vinylphenyl sulfuricacid, ethylene phosphonic acid, vinyl phosphoric acid, vinyl benzoicacid, 2-acrylamido-2-methyl-1-propanesulfonic acid, the like, orcombinations thereof.

Non-limiting examples of hydrophobic monomers that can be used includestyrene, p-methyl styrene, methyl methacrylate, hexyl acrylate, hexylmethacrylate, butyl acrylate, butyl methacrylate, ethyl acrylate, ethylmethacrylate, propyl acrylate, propyl methacrylate, octadecyl acrylate,octadecyl methacrylate, stearyl methacrylate, vinylbenzyl chloride,isobornyl acrylate, tetrahydrofurfuryl acrylate, 2-phenoxyethylmethacrylate, ethoxylated nonyl phenol methacrylate, isobornylmethacrylate, cyclohexyl methacrylate, t-butyl methacrylate, n-octylmethacrylate, lauryl methacrylate, trydecyl methacrylate, alkoxylatedtetrahydrofurfuryl acrylate, isodecyl acrylate, isobomylmethacrylate,the like, or combinations thereof.

The styrene acrylic polymer can have a weight average molecular weight(Mw) from about 3,000 g/mol to about 30,000 g/mol. In yet otherexamples, the styrene acrylic polymer can have an Mw from about 4,000g/mol to about 25,000 g/mol, or from about 4,500 g/mol to about 22,000g/mol.

In each instance where molecular weight is referred to, it is to beunderstood that this refers to weight average molecular weight in g/mol.

Further, in some examples, the styrene acrylic polymer can have an acidnumber or acid value from about 120 mg KOH/g to about 300 mg KOH/g. Inyet other examples, the styrene acrylic polymer can have an acid numberfrom about 140 mg KOH/g to about 260 mg KOH/g, from about 160 mg KOH/gto about 240 mg KOH/g, or from about 180 mg KOH/g to about 230 mg KOH/g.An acid number can be defined as the number of milligrams of potassiumhydroxide to neutralize 1 gram of the substance.

In some examples, the amount of styrene acrylic polymer in the coloredink composition(s) can be from about 0.1 wt % to about 20 wt % based onthe total weight of the colored ink composition(s), or from about 0.5 wt% to about 10 wt % based on the total weight of the colored inkcomposition(s), or from about 1 wt % to about 5 wt % based on the totalweight of the colored ink composition(s).

In some examples, the amount of styrene acrylic polymer in the coloredink composition(s) can be based on the amount of the colorant(s) in thecolored ink composition(s). Thus, in some examples, the colorant(s) andthe styrene acrylic polymer can be present in the colored inkcomposition(s) at a particular weight ratio. In some specific examples,the pigment and styrene acrylic polymer can be present at a weight ratioof from 1:1 to 10:1. In other examples, the pigment and the styreneacrylic polymer can be present at a weight ratio of from about 2:1 toabout 10:1. In yet other examples, the pigment and the styrene acrylicpolymer can be present at a weight ratio of from about 3:1 to about 6:1.

Detailing Agent

In some examples, the three-dimensional printing methods andcompositions described herein include a detailing agent. The detailingagent comprises: at least one co-solvent; at least one surfactant; atleast one anti-kogation agent; at least one chelating agent; at leastone biocide; and water.

In some examples, the detailing agent can further include otheradditives including at least one buffer solution, at least onedispersant, at least one stabilizer, and/or combinations thereof.

In some examples, the detailing agent is added in the three-dimensionalprinting composition in an amount of from about 1 wt % to about 30 wt %based on the total weight of the three-dimensional printing composition,or from about 5 wt % to about 25 wt %, or from about 8 wt % to about 20wt %, or less than about 35 wt %, or less than about 25 wt %, or lessthan about 20 wt %, or less than about 15 wt %, or less than about 10 wt%, or at least about 1 wt %, or at least about 3 wt %, or at least about5 wt %, or at least about 8 wt %, or at least about 10 wt %, or at leastabout 15 wt %, or at least about 20 wt %, or at least about 30 wt %, orat least about 35 wt %.

Marking Agent

In some examples, the three-dimensional printing kits, methods, andcompositions described herein include a marking agent. The marking agentcomprises: at least one marking component which is a fluorescent coloragent that is activated by ultraviolet radiation to emit light in thevisible range of from about 400 nm to about 780 nm, at least oneco-solvent; at least one surfactant; at least one anti-kogation agent;at least one chelating agent; at least one biocide; and water.

In some examples, the marking agent can further include other additivesincluding at least one buffer solution, at least one dispersant, atleast one stabilizer, and/or combinations thereof.

“Marking agent,” as used herein, can be defined as a compound that canfluoresce or phosphor. “Phosphor” is a term generally used to refer toinorganic photoluminescent materials (fluorescent or phosphorescent)that are generally used as small crystalline particles that appear likea powder before mixing. The use of “phosphor” is generalized toencompass all particle-based photoluminescent materials, which includesquantum dots, other spectrum-converting nanoparticles and theirconjugates, and other fluorescent or phosphorescent materials other thanorganic fluorescent or phosphorescent dyes. “Dye,” as used herein,refers to fluorescent or phosphorescent materials that are mostlydistributed at a molecular level in solutions (e.g., polymers, sol gels,low temperature glasses, liquids or gels, and other translucentmaterials in a wide variety of shapes). Dyes here primarily includeorganic dyes that are dissolved in polymers or other media and thenformed into particles, even though they may be used for similar purposesas phosphors or QDs.

In some examples, the marking agent includes at least one markingcomponent, water, and at least one co-solvent.

The marking agent can be used to form 3D printed parts for the purposeof part tracking, security marking, and/or other several applicationsthat can require uniquely identifying 3D printed parts.

In some examples, the marking agent can be prepared by mixing allmarking agent components first and then adding the marking component inlast. All components are mixed together until fully dissolved. Then theagent is filtered and then ready for use.

In some examples, the making agent comprises the marking component is afluorescent color agent that can be activated by UV radiation butotherwise is substantially not clearly visible in the visible lightspectrum. However, under excitation by ultraviolet light, thefluorescent color agent can emit light in the visible range (i.e., about400-about 780 nm), which can be for example, blue, red, or green incolor. The fluorescent color agent can be excited by ultravioletradiation (i.e., about 200-about 400 nm range, or about 300-about 400nm, or about 350-about 400 nm). The fluorescent color agent can be a dyeor a pigment, which can be one or more of any of the below markingcomponent options.

As used herein, “fluorescent color agent” and “marking component” areinterchangeable.

In some examples, the fluorescent color agent or marking component issubstantially invisible in ambient light. Ambient light, as used herein,is visible light in the range of from about 380 nm to about 740 nm.

In some examples, the fluorescent color agent/marking component can bedistyrylbenzenes, distyrylbiphenyls, divinylstilbenes,triazinylaminostilbenes, stilbenyl-2H-triazoles, benzoxazoles, furans,benzo[b]furans, benzimidazoles, 1,3-diphenyl-2-pirazolines, coumarins,naphthalimides, organic europium (III) complexes, fluorescein,rhodamines, or mixtures thereof.

The rhodamines, as used herein, fluoresce in visible range of from about400 nm to about 780 nm.

In some examples, the fluorescent color agent/the marking component isactivated by ultraviolet radiation in the range of from about 200 nm toabout 400 nm. This activation causes the otherwise substantiallyinvisible fluorescent color agent to “fluoresce” and become visible tothe naked eye.

In some examples, the fluorescent color agent/marking component can behexasodium-2,2′-[vinylenebis[3-sulfonato-4,1-phenylene)imino[6-(diethylamino)-1,3,5-triazine4,2-diyl]imino]]bis(benzene-1,4-disulphonate).

In some examples, fluorescent color agent/the marking component cancomprise Tinopal® SFP, Tinopal® CBS SP, Tinopal® CBS-CL, Tinopal® CBS-X,Tinopal® DMA-X, Tinopal® NFWLIQ, or combinations thereof—all availablefrom BASF Corp.

In some examples, the fluorescent color agent/marking component in themarking agent can be optical brighteners. In some examples, opticalbrighteners can include compounds with fluorescence or phosphorescencebetween 370 and 1100 nm. The optical brighteners can include Uvitex® OB,Uvitex® OB-C, Uvitex® OB-P, Uvitex® NFW, Uvitex® FP, Uvitex® FP-C,Tinopal® SFP, Tinopal® MSP, or combinations thereof, all of which arecommercially available from BASF Corp.

Other examples of optical brighteners can be found in Kirk-OthmerEncyclopedia of Chemical Technology, 4, “Fluorescent Brighteners”, pp.213-225 (1978), and can include stilbene derivatives such as4,4′-bis(triazin-2-ylamino)stilbene-2,2′-disulfonic acid derivativeswherein the triazinyl groups are substituted with suitable substituents,including substituents such as anilino, sulfanilic acid, metanilic acid,methylamino, N-methyl-N-hydroxyethylamino, bis (hydroxyethylamino),morpholino, diethylamino, and the like; mono(azol-2-yl)stilbenes such as2-(stilben-4-yl)naphthotriazoles and2-(4-phenylstilber-4-yl)benzoxazoles; bis(azol-2-yl)stilbenes such as4,4′-bis(triazol-2-yl)stilbene-2,2′-disulfonic acids; styryl derivativesof benzene and biphenyl such as 1,4-bis(styryl)benzenes and 4,4′bis(styryl)biphenyls; pyrazolines such as 1,3-diphenyl-2-pyrazolines;bis(benzazol-2-yl) derivatives having as phenyl ring substituents alkyl,COO-alkyl, and SO.sub.2-alkyl; bis(benzoxazol-2-yl) derivatives;bis(benzimidazol-2-yl) derivatives such as2-(benzofuran-2-yl)benzimidazoles; coumarins such as 7-hydroxy and7-(substituted amino) coumarins, 4-methyl-7-amino-coumarin derivatives,esculetin, .beta.-methylumbelliferone,3-phenyl-7-(triazin-2-ylamino)coumarins, 3-phenyl-7-aminocoumarin,3-phenyl-7-(azol-2-yl)coumarins, and 3,7-bis(azolyl)coumarins;carbostyrils, naphthalimides, alkoxynaphthalimides, derivatives ofdibenzothiophene-5,5-dioxide, pyrene derivatives, and pyridotriazoles.

In some examples, the fluorescent color agent/the marking component canalso include organic metal complexes. The preferred organic metalcomplexes can be derived from europium, zinc, iridium, aluminum, galliumand terbium. Examples of such materials can include:tris(benzoylacetonato)mono(phenanthroline)europium (III),tris(dibenzoylmethane)mono(phenanthroline)europium (III),tris(dibenzoylmethane)mono(5-aminophenanthroline)europium (III),tris(dinaphthoylmethane)mono(phenanthroline)europium (III),tris(dibiphenoylmethane)mono(phenanthroline)europium (III),tris(dibenzoylmethane)mono(4,7-dimethylphenanthroline)europium (III),tris(dibenzoylmethane)mono(4,7-diphenylphenanthroline)europium (III),bis(8-hydroxyquinolato)zinc bis(2-methyl-8-hydroxyquinolato)zinc,iridium (III) tris(2-phenylpyridinato-N,C.sup.2′)picolate, Iridium (III)tris(2-(4-tolyl)pyridinato-N,C.sup.2′)picolinate, iridium (III)bis(2-(4,6-difluorophenyl)pyridinato-N,C.sup.2′), iridium (III)bis(2-(2′-benzothienyl)pyridinato-N,C.sup.3′)(acetylacetonate),tris(8-hydroxyquinolato)aluminum (III),tris(2-methyl-8-hydroxyquinolato)aluminum (III),tris(8-hydroxyquinolato)gallium (III),tris(2-methyl-8-hydroxyquinolato)gallium (III),tris(3-methyl-1-phenyl-4-trimethyl-acetyl-5-pyrazoline)terbium (III), ormixtures thereof.

In some examples, examples of fluorescent dyes that can comprise thefluorescent color agent/the marking component can be fluorescentbrighteners containing sulfo groups, in particular stilbene fluorescentbrighteners, especially those of the type of thebis-triazinylaminostilbenedisulfonic acids, the bis-styrylbiphenyls, thebis-styrylbenzenes and the bis-triazolylstilbenedisulfonic acids. Thefluorescent brighteners containing sulfonic acid groups can be in theform of their metal salts, for example, lithium, potassium, magnesium orsodium salts, and also ammonium, amine or alkanolamine salts.Fluorescent brightener compounds which have been partially acidified orfluorescent brighteners in the form of the free acid can be used.

Other examples of fluorescent dyes which can be used to prepare themarking agent are fluorescent naphthalimide dyes for example, MortonFluorescent Yellow G (Color Index 75), Fluorol 7GA (ColorIndex-Fluorescent brightening agent 75), Calcofluor Yellow (ColorIndex-Fluorescent brightening agent No. 4) and Azosol Brilliant Yellow 6GF (Color Index-Solvent Yellow 44), and the fluorescent cuomarin dyes,for example, Calcofluor White RW (Color Index-Fluorescent brighteningagent 68) and Blancophor White AW (Color Index-Fluorescent brighteningagent 68). Other useful fluorescent dyes include Rhodanine B, Rhodanine6 GDN, Auramine, Eosine G, Calcofluor White ST, Pontamine White RT,Pontamine White BTS, Rhodamine Bx, Phthalocyamine, Alkali Blue G,Phthalocyamine, Rhoamine 7G, Rhodamine FB, Rhodamine S, Rhodamine 5G,Bright Yellow 3G, Teteramethyl Rhodamine, Rhodamine FG, Rhodamine F4G,Fanal Pink D, Fanal Violet D, Flexo Yellow 110, Lumogen Yellow D,Fluorol Green Gold, Fluorol Yellow, Thermoplast F-Orange, orcombinations thereof.

In some examples, the fluorescent color agent/the marking component canbe added to the marking agent in an amount of from about 0.1 wt % toabout 10 wt % based on the total weight of the marking agent, or lessthan about 10 wt %, or less than about 9 wt %, or less than about 8 wt%, or less than about 7 wt %, or less than about 6 wt %, or less thanabout 5 wt %, or less than about 4 wt %.

In some examples, the marking agent is added in the three-dimensionalprinting part in an amount of from about 0.1 wt % to about 30 wt % basedon the total weight of the three-dimensional part, or from about 0.5 wt% to about 20 wt %, or from about 1.5 wt % to about 15 wt %, or fromabout 2 wt % to about 10 wt %, or less than about 35 wt %, or less thanabout 25 wt %, or less than about 20 wt %, or less than about 15 wt %,or less than about 10 wt %, or less than about 8 wt %, or less thanabout 5 wt %.

Co-Solvent(s)

In some examples, each of the agent(s)/composition(s) described hereincan include at least one co-solvent. The co-solvent can be present in anamount ranging from about 0.1 wt % to about 50 wt % based on the totalweight of each of the agent(s)/composition(s), or less than about 60 wt%, or less than about 50 wt %, or less than about 45 wt %, or less thanabout 40 wt %, or less than about 35 wt %, or less than about 30 wt %,or less than about 25 wt %, or less than about 20 wt %, or less thanabout 15 wt %, or less than about 10 wt %, or less than about 5 wt %, orat least about 10 wt %, or at least about 15 wt %, or at least about 20wt %, or at least about 25 wt %, or at least about 30 wt %, or at leastabout 35 wt %, or at least about 40 wt %, or at least about 45 wt %, orat least about 50 wt %.

Some examples of co-solvents can include 2-pyrrolidinone,hydroxyethyl-2-pyrrolidone, diethylene glycol, 2-methyl-1,3-propanediol,tetraethylene glycol, tripropylene glycol methyl ether, dipropyleneglycol methyl ether, tripropylene glycol butyl ether, dipropylene glycolbutyl ether, triethylene glycol butyl ether, 1,2-hexanediol,2-hydroxyethyl pyrrolidinone, 2-hydroxyethyl-2-pyrrolidinone,1,6-hexanediol, and combinations thereof.

Additive(s)

In some examples, the agent(s)/composition(s) may further include abuffer solution, a surfactant, a dispersant, an anti-kogation agent, adispersing additive, a biocide, a chelating agent, at least onechelating agent, and combinations thereof.

In some examples, the agent(s)/composition(s) may further include buffersolution(s). In some examples, the buffer solution(s) can withstandsmall changes (e.g., less than 1) in pH when small quantities of awater-soluble acid or a water-soluble base are added to a compositioncontaining the buffer solution(s). The buffer solution(s) can have pHranges from about 5 to about 9.5, or from about 7 to about 9, or fromabout 7.5 to about 8.5.

In some examples, the buffer solution(s) can be added to theagent(s)/composition(s) in amounts ranging from about 0.01 wt % to about20 wt %, or from 0.1 wt % to about 15 wt %, or from about 0.1 wt % toabout 10 wt % based on the total weight of the agent(s)/composition(s).

In some examples, the buffer solution(s) can include at least onepoly-hydroxy functional amine.

In some examples, the buffer solution(s) can be 2-[4-(2-hydroxyethyl)piperazin-1-yl] ethane sulfonic acid,2-amino-2-(hydroxymethyl)-1,3-propanediol (TRIZMA® sold bySigma-Aldrich), 3-morpholinopropanesulfonic acid, triethanolamine,2-[bis-(2-hydroxyethyl)-amino]-2-hydroxymethyl propane-1,3-diol (bistris methane), N-methyl-D-glucamine,N,N,N′N′-tetrakis-(2-hydroxyethyl)-ethylenediamine andN,N,N′N′-tetrakis-(2-hydroxypropyl)-ethylenediamine, beta-alanine,betaine, or mixtures thereof.

In some examples, the buffer solution(s) can be2-amino-2-(hydroxymethyl)-1,3-propanediol (TRIZMA® sold bySigma-Aldrich), beta-alanine, betaine, or mixtures thereof.

The agent(s)/composition(s) in some examples can be dispersed with adispersing additive. The dispersing additive can help to uniformlydistribute colorant(s) throughout the agent(s)/composition(s). Thedispersing additive may also aid in the wetting of theagent(s)/composition(s) onto any other applied agent(s)/composition(s)and/or the layer(s) of the build material.

The dispersing additive may be present in the agent(s)/composition(s) inan amount ranging from about 0.01 wt % to about 2 wt % based on thetotal weight of the agent(s)/composition(s), or less than about 1.5 wt%, or less than about 1 wt %, or at least 0.01 wt %, or at least about0.1 wt %, or at least about 0.5 wt %.

Some examples of the dispersing additive can include a water solubleacrylic acid polymer (e.g., CARBOSPERSE® K7028 available from Lubrizol),a high molecular weight block copolymer with pigment affinic groups(e.g., DISPERBYK®-190 available BYK Additives and Instruments), andcombinations thereof.

The agent(s)/composition(s) can further include the dispersant toprovide particular wetting properties when applied to the layer(s) ofthe build material. The dispersant can help uniformly distribute theink(s) on the layer(s) of the build material.

The dispersant may be present in the agent(s)/composition(s) in anamount ranging from about 0.01 wt % to about 2 wt % based on the totalweight of the agent(s)/composition(s), or less than about 1.5 wt %, orless than about 1 wt %, or at least 0.01 wt %, or at least about 0.1 wt%, or at least about 0.5 wt %.

The dispersant may be non-ionic, cationic, anionic, or combinationsthereof. Some examples of the dispersant include a self-emulsifiable,non-ionic wetting agent based on acetylenic diol chemistry (e.g.,SURFYNOL® SEF from Air Products and Chemicals, Inc.), an ethoxylatedlow-foam wetting agent (e.g., SURFYNOL® 440 and SURFYNOL®465 from AirProducts and Chemicals, Inc.), a non-ionic acetylenic diol surfaceactive agent (e.g., SURFYNOL®104 from Air Products and Chemicals, Inc.),a non-ionic, alkylphenylethoxylate and solvent free surfactant blend(e.g., SURFYNOL® CT-211 from Air Products and Chemicals, Inc.), anon-ionic organic surfactant (e.g., TEGO® Wet 510 from Evonik IndustriesAG), a non-ionic fluorosurfactant (e.g., CAPSTONE® fluorosurfactantsfrom DuPont, previously known as ZONYL FSO, POLYFOX™ PF-154N from OmnovaSolutions Inc.), non-ionic a secondary alcohol ethoxylate (e.g.,TERGITOL® 15-S-5, TERGITOL® 15-S-7, TERGITOL®15-S-9, andTERGITOL®15-S-30 all from Dow Chemical Company), a water-solublenon-ionic surfactant (e.g., TERGITOL® TMN-6), and combinations thereof.Examples of anionic dispersants include those in the DOWFAX™ family(from Dow Chemical Company), and examples of cationic dispersantsinclude dodecyltrimethylammonium chloride and hexadecyldimethylammoniumchloride. Combinations of any of the previously listed dispersants mayalso be used.

Examples of anti-kogation agents include oleth-3-phosphate orpolyoxyethyene (3) oleyl mono/di-phosphate (e.g., CRODAFOS® N-3A fromCroda, now CRODAFOS® 03A), aqueous dispersion of fumed alumina or fumedsilica (e.g., CAB-O-SPERSE® from Cabot Corp.), a metalchelator/chelating agent, such as methylglycinediacetic acid (e.g.,TRILON® M from BASF Corp.), and combinations thereof.

The anti-kogation agents may be present in the agent(s)/composition(s)in an amount ranging from about 0.01 wt % to about 2 wt % based on thetotal weight of the agent(s)/composition(s), or less than about 1.5 wt%, or less than about 1 wt %, or at least 0.01 wt %, or at least about0.1 wt %, or at least about 0.5 wt %.

Examples of biocides include 1,2-benzisothiazolin-3-one as the activeingredient in ACTICIDE® B-20 (available from Thor GmbH),2-methyl-4-isothiazolin-3-one as the active ingredient in ACTICIDE® M-20(available from Thor GmbH), an aqueous solution of1,2-benzisothiazolin-3-one (e.g., PROXEL® GXL from Arch Chemicals,Inc.), quaternary ammonium compounds (e.g., BARDAC®2250 and 2280,BARQUAT®50-65B, and CARBOQUAT®250-T, all from Lonza Ltd. Corp.), anaqueous solution of methylisothiazolone (e.g., KORDEK® MLX from The DowChemical Co.), and combinations thereof.

The biocides may be present in the agent(s)/composition(s) in an amountranging from about 0.01 wt % to about 2 wt % based on the total weightof the agent(s)/composition(s), or less than about 1.5 wt %, or lessthan about 1 wt %, or at least 0.01 wt %, or at least about 0.1 wt %, orat least about 0.5 wt %.

The agent(s)/composition(s) may also include a binder or otheradditives, such as a humectant and lubricant (e.g., LIPONIC® EG-1(LEG-1) from Lipo Chemicals) or a chelating agent (e.g., disodiumethylenediaminetetraacetic acid (EDTA-Na)).

The amounts of the above additives in the first fusing agent, the secondfusing agent, the color ink composition, and the detailing agent cantotal up to about 20 wt % based on the total weight of one of theagent(s)/composition(s).

Water

The balance of the agent(s) and composition(s) is water. As such, theamount of water may vary depending upon the amounts of thenanoparticle(s), near infrared absorbing compound(s), and colorant(s).

In some examples, water can be present in the agent(s)/composition(s) inamounts greater than about 50 wt % based on the total weight of theagent(s)/composition(s). In some examples, the water can be present inthe agent(s)/composition(s) in amounts from about 50 wt % to about 90 wt% based on the total weight of the agent(s)/composition(s). In otherexamples, the agent(s)/composition(s) can include water in an amount offrom about 60 wt % to about 90 wt % based on the total weight of theagent(s)/composition(s). In further examples, theagent(s)/composition(s) can include from about 70 wt % to about 85 wt %water.

Agent(s)/Composition(s) Preparation

In some examples, the first fusing agent may be prepared by mixing thenanoparticles described above, a co-solvent, water.

In some examples, the second fusing agent may be prepared by mixing thenear infrared absorbing compound described above, a co-solvent, water.

In some examples, the color agent may be prepared by mixing water, aco-solvent, and one or more colorant(s) dispersed in a binder solution.

In some examples, the detailing agent may be prepared by mixing the aco-solvent and water.

In some examples, the marking agent may be prepared by mixing at leastone marking component with water, at least one co-solvent, and at leastone surfactant. Other components, such as, buffering agents, biocides,can be mixed in as well.

In some examples, the first fusing agent, the second fusing agent, thecolor ink composition, and the detailing agent can further be mixed withone or more of the additives described above.

In some examples, the first fusing agent may be filtered to obtain thenanoparticle aqueous ink composition used in the 3D printing methodsdescribed herein.

In some examples, the colored ink(s) may be prepared by first millingany colorant(s) in water and a dispersant additive until a particle sizeof from about 0.01 nm to about 1000 nm of the colorant is obtained.Milling forms a colorant concentrate.

A balance of water may be added to the agent(s)/composition(s) in asuitable amount, taking into account the weight percent of colorantconcentrate that is to be added.

Build Material

In some examples, the powder build material 206 can be selected from thegroup consisting of polymeric powder, polymeric-ceramic compositepowder, and combinations thereof.

In some examples, the build material may be a polymeric build material.As used herein, the term “polymeric build material” may refer tocrystalline or semi-crystalline polymer particles or composite particlesmade up of polymer and ceramic.

Any of the particles may be in powder form. Examples of semi-crystallinepolymers include semi-crystalline thermoplastic materials with a wideprocessing window of greater than 5° C. (i.e., the temperature rangebetween the melting point and the re-crystallization temperature). Somespecific examples of the semi-crystalline thermoplastic materialsinclude polyamides (PAs) (e.g., PA 11/nylon 11, PA 12/nylon 12, PA6/nylon 6, PA 8/nylon 8, PA 9/nylon 9, PA 66/nylon 66, PA 612/nylon 612,PA 812/nylon 812, PA 912/nylon 912, etc.).

Other examples of crystalline or semi-crystalline polymers suitable foruse as the build material particles include polyethylene, polyethyleneoxide, polypropylene, polyoxomethylene (i.e., polyacetals), andcombinations thereof. Still other examples of suitable build materialparticles include polystyrene, polycarbonate, polyester, polyurethanes,other engineering plastics, and combinations thereof. It should be notedthat the “combinations” of the polymers described herein can includeblends, mixtures, block copolymers, random copolymers, alternatingcopolymers, periodic polymers, and mixtures thereof.

In some examples, the build material may be a polymeric-ceramiccomposite powder. The “polymeric-ceramic composite” powder can includeone or more of the polymers described above in combination with one ormore ceramic materials in the form of a composite. The polymeric-ceramiccomposite can include any weight combination of polymeric material andceramic material. For example, the polymeric material can be present inan amount of up to 99 wt % with the balance being ceramic material orthe ceramic material can be present in an amount of up to 99 wt % withthe balance being polymeric material.

In some examples, the ceramic material can be selected from the groupconsisting of silica, fused silica, quartz, alumina silicates, magnesiasilicates, boria silicates, and mixtures thereof. Examples of ceramicmaterials can include metal oxides, inorganic glasses, carbides,nitrides, and borides. Some specific examples can include alumina(Al2O3), Na₂O/CaO/Si02glass (soda-lime glass), silicon nitride (Si3N4),silicon dioxide (SiO₂), zirconia (ZrO₂), titanium dioxide (T1O2), glassfrit materials, or combinations thereof. As an example of one suitablecombination, 30 wt % glass may be mixed with 70 wt % alumina.

The polymeric material or the polymeric-ceramic composite material maybe made up of similarly sized particles or differently sized particles.The term “size” or “particle size,” as used herein, refers to thediameter of a substantially spherical particle, or the average diameterof a non-spherical particle (i.e., the average of multiple diametersacross the particle), or the effective diameter of a non-sphericalparticle (i.e., the diameter of a sphere with the same mass and densityas the non-spherical particle). A substantially spherical particle(i.e., spherical or near-spherical) has a sphericity of >0.84. Thus, anyindividual particles having a sphericity of <0.84 are considerednon-spherical (irregularly shaped).

In some examples, the particle size of the polymeric material or thepolymeric-ceramic composite material particles can be from about 10 μmto about 500 μm, or less than about 450 μm, or less than about 400 μm,or less than about 350 μm, or less than about 300 μm, or less than about250 μm, or less than about 200 μm, or less than about 150 μm, or lessthan about 150 μm, or less than about 90 μm, or less than about 80 μm,or at least about 10 μm, or at least about 20 μm, or at least about 30μm, or at least about 40 μm, or at least about 50 μm, or at least about60 μm, or at least about 70 μm, or at least about 80 μm, or at leastabout 90 μm, or at least about 100 μm, or at least about 110 μm, or atleast about 120 μm, or at least about 130 μm, or at least about 140 μm,or at least about 150 μm, or at least about 160 μm, or at least about170 μm, or at least about 180 μm, or at least about 190 μm.

The build material particles may have a melting point or softening pointranging from about 50° C. to about 400° C. As an example, the buildmaterial particles may be a polyamide having a melting point of 180° C.The build material particles may be made up of similarly sized particlesor differently sized particles. The term “size”, as used herein withregard to the build material particles, refers to the diameter of aspherical particle, or the average diameter of a non-spherical particle(i.e., the average of multiple diameters across the particle), or thevolume-weighted mean diameter of a particle distribution.

In some examples, the build material can include one or more fillers.The fillers can be selected from glass beads, fumed silica, natural orsynthetic fibers, glass fibers, carbon fibers, boron fibers, Kevlar®fiber, PTFE fiber, ceramic fibers, silicon carbide fibers, aluminafiber, and combinations thereof. In some examples, the filler caninclude inorganic oxides, carbides, borides and nitrides having a Knoophardness of at least 1200. In some examples, the filler are inorganicoxides, nitrides, borides and carbides of zirconium, tantalum, titanium,tungsten, boron, aluminum and beryllium. In some examples, the filler issilicon carbide and aluminum oxide.

The fillers can be added to the build material in an amount of up toabout 30 wt % based on the total amount of the build material, or lessthan about 25 wt %, or less than about 20 wt %, or less than about 15 wt%, or less than about 10 wt %.

3D Printed Part/Object

The present disclosure refers also to an article, or final 3D object,that has been obtained according to three-dimensional printing methodsdescribed herein.

The 3D printed article can comprise a core substrate made of a polymericbuild material that has been fused with a second fusing agentcomposition; a first layer applied on the surface of the core substrate,comprising a polymeric build material fused with a first fusing agentcomposition including metal oxide nanoparticles dispersed in a liquidvehicle or fused with second fusing agent; and a second layer comprisinga polymeric build material fused with a colored ink composition and witha first fusing agent.

In some examples, the 3D printed article can further comprise additionallayers of a detailing agent.

In some examples, the 3D printed article can further comprise additionallayers of a marking agent. The marking agent comprises a markingcomponent which is a substantially invisible (in ambient light)fluorescent color agent that is activated by absorption of ultravioletradiation to emit light in the visible range of from about 400 nm toabout 780 nm.

In some examples, the 3D printed article can further comprise additionallayers of a colored agent.

In some examples, once the core and the first layer is formed, layers ofthe detailing agent, marking agent, and/or color agent can be present inany order. It is to be understood that the core and any other layers canhave one or multiple layers to form a strong consolidated part. It isfurther to be understood that the marking agent can be appliedseparately or mixed together with the first fusing agent, the secondfusing agent, the detailing agent, and/or the color agent to form thecore and/or any of the 3D printed part layers.

The core layer might be considered as providing the mechanical integrityof the final 3D object. Due to the chemical nature of the second fusingagent it contains, the core layer might have a black color. The firstlayer could be defined as a transition layer that would match lightnessof the target color. The first layer can provide the object with a white(or slightly tinted) exterior surface. The first layer can also have theeffect to optically isolate the core layer that it covers. The secondlayer and the third layer (when present) would provide color to thefinal object and can also be thus referred to as the “colored layer”.The color would be provided by the colorant contained in the inkcomposition.

It is to be understood that the final 3D object is made layer by layer,the layers are stacked over each other i.e., by depositing one layerover the other. This means thus that the core layer (or substrate) isnot necessarily built first, but the external layer or second layersmight be built first. The layer that is formed with the second fusingagent composition may be a first or primer layer (upon which otherlayers are formed) or may be an outer layer (or one of several layersforming an outer region) of the part that is formed.

The article of final 3D object is made several layers and each layer ismade of several parts. Each layer is sequentially formed by selectivelypatterning respective build material layers with the first fusing agentand first fusing agent, depending of the nature of the part wanted, andexposing each patterned layer to electromagnetic radiation. In someexamples, each layer can have a different but substantially uniformthickness. In an example, the thickness of each layer in the part canrange from about 10 μm to about 500 μm, although thinner or thickerlayers may also be used. In some other examples, the thickness of thecore layer can range from about 500 μm to about 1 cm, although thinneror thicker layers may also be used.

Unless otherwise stated, any feature described hereinabove can becombined with any example or any other feature described herein.

In describing and claiming the examples disclosed herein, the singularforms “a,” “an,” and “the” include plural referents unless the contextclearly dictates otherwise.

It is to be understood that concentrations, amounts, and other numericaldata may be expressed or presented herein in range formats. It is to beunderstood that such range formats are used merely for convenience andbrevity and thus should be interpreted flexibly to include not just thenumerical values explicitly recited as the end points of the range, butalso to include all the individual numerical values or sub-rangesencompassed within that range as if each numerical value and sub-rangeis explicitly recited. As an illustration, a numerical range of “about 1wt % to about 5 wt %” should be interpreted to include not just theexplicitly recited values of about 1 wt % to about 5 wt %, but alsoinclude individual values and subranges within the indicated range.Thus, included in this numerical range are individual values such as 2,3.5, and 4 and sub-ranges such as from 1-3, from 2-4, and from 3-5, etc.This same applies to ranges reciting a single numerical value.

Reference throughout the specification to “one example,” “someexamples,” “another example,” “an example,” and so forth, means that aparticular element (e.g., feature, structure, and/or characteristic)described in connection with the example is included in at least oneexample described herein, and may or may not be present in otherexamples. In addition, it is to be understood that the describedelements for any example may be combined in any suitable manner in thevarious examples unless the context clearly dictates otherwise.

Unless otherwise stated, references herein to “wt %” of a component areto the weight of that component as a percentage of the whole compositioncomprising that component. For example, references herein to “wt %” of,for example, a solid material such as polyurethane(s) or colorant(s)dispersed in a liquid composition are to the weight percentage of thosesolids in the composition, and not to the amount of that solid as apercentage of the total non-volatile solids of the composition.

If a standard test is mentioned herein, unless otherwise stated, theversion of the test to be referred to is the most recent at the time offiling this patent application.

All amounts disclosed herein and in the examples below are in wt %unless indicated otherwise.

To further illustrate the present disclosure, examples are given herein.It is to be understood that these examples are provided for illustrativereasons and are not to be construed as limiting the scope of the presentdisclosure.

EXAMPLES Example 1

The following Table 1 shows an example first fusing agent composition.

TABLE 1 Component Comp. A (wt %) Near Infrared Absorber  5-12 OrganicSolvent  15-25 Surfactant 0.1-5  Biocide 0.01-0.1 Complexing Agent0.001-0.01 water Balance

Example 2

The following Table 2 shows an example second fusing agent composition.

TABLE 2 Component Comp. B (wt %) Organic Solvent 20-35 Surfactant 1-5Anti-kogation agent and chelating agent 0.1-1  Biocide 0.1-1  Near IRAbsorbing Agent 3-8 Water Balance

Example 3

The following Table 3 shows an example detailing agent composition.

TABLE 3 Component Comp. C (wt %) Organic Solvent  10-20 Surfactant 0.5-1Anti-kogation agent and chelating agent 0.1-1 Biocide 0.1-1 Colorant(s)  0-10 Water Balance

Example 4

The following Tables 4-7 show examples of cyan ink, yellow ink, magentaink, and black ink compositions.

TABLE 4 Component Comp. D (wt %) Cyan Colorant  1-10 Organic Solvent30-60 Anti-Kogation Agent 0.01-0.05 Buffering Agent 0.1-0.5 Dispersant 0-0.1 Surfactant 0.1-1  Biocide  0-0.1 Chelating Agent 0.01-0.1  Waterbalance

TABLE 5 Component Comp. E (wt %) Yellow Colorant 1-10  Organic Solvent30-60  Anti-Kogation Agent  0-0.05 Buffering Agent 0.05-0.5   Dispersant0-0.1 Surfactant 0.1-1    Biocide 0-0.1 Chelating Agent 0.01-0.1   Waterbalance

TABLE 6 Component Comp. F (wt %) Magenta Colorant  1-10 Organic Solvent 30-60 Anti-Kogation Agent 0.01-0.5 Buffering Agent 0.05-0.5 Dispersant  0-0.1 Surfactant 0.1-1  Biocide   0-0.1 Chelating Agent 0.01-0.1 Waterbalance

TABLE 7 Component Comp. G Black Colorant  1-10 Oxidizer/Colorfastness1-5 Organic Solvent 30-60 Anti-Kogation Agent  0-0.1 Buffering Agent0.05-0.5  Surfactant 0.1-1  Biocide  0-0.1 Chelating Agent 0.01-0.1 Water balance

Example 5

The following Table 8 shows an example marking agent composition.

TABLE 8 Component Comp. C (wt %) Marking Component  1-8 Organic Solvent 10-20 Surfactant 0.5-2 Anti-kogation agent and chelating agent 0.1-1Buffering Agent 0.1-1 Biocide 0.1-1 Water Balance

Example 6

A 3D printed part was produced using example compositions in Tables 1-8.A photograph of the 3D printed part is shown in FIG. 3. The barcode (ormark) visible in FIG. 3 was printed on the 3D printed part by using amarking agent composition from Table 8 while using Tinopal® SFP as themarking component. The 3D printed part was produced by first forming acore using the second fusing agent, then layers of the first fusingagent, and then layers of the marking agent to form the barcode.

The marking agent can be used to form 3D printed parts for the purposeof part tracking, security marking, and/or other several applicationsthat can require uniquely identifying 3D printed parts.

Although described specifically throughout the entirety of the instantdisclosure, representative examples of the present disclosure haveutility over a wide range of applications, and the above discussion isnot intended and should not be construed to be limiting, but is offeredas an illustrative discussion of examples of the disclosure.

What is claimed is:
 1. A multi-fluid kit for three-dimensional printingcomprising: a marking agent comprising a marking component which is afluorescent color agent that is activated by ultraviolet radiation toemit light in the visible range of from about 400 nm to about 780 nm; afirst fusing agent; a second fusing agent different from the firstfusing agent; and a detailing agent.
 2. The multi-fluid kit of claim 1,wherein: the fluorescent color agent is substantially invisible inambient light; and the fluorescent color agent comprisesdistyrylbenzenes, distyrylbiphenyls, divinylstilbenes,triazinylaminostilbenes, stilbenyl-2H-triazoles, benzoxazoles, furans,benzo[b]furans, benzimidazoles, 1,3-diphenyl-2-pirazolines, coumarins,naphthalimides, organic europium (III) complexes, fluorescein,rhodamines, or mixtures thereof.
 3. The multi-fluid kit of claim 1,wherein: the fluorescent color agent is activated by ultravioletradiation in the range of from about 200 nm to about 400 nm; and thefluorescent color agent compriseshexasodium-2,2′-[vinylenebis[3-sulfonato-4,1-phenylene)imino[6-(diethylamino)-1,3,5-triazine4,2-diyl]imino]]bis(benzene-1,4-disulphonate).4. The multi-fluid kit of claim 1, wherein the first fusing agentcomprises at least one nanoparticle, wherein the nanoparticle comprisesat least one metal oxide, which absorbs infrared light in a range offrom about 780 nm to about 2300 nm and is shown in formula (1):MmM′On  (1) wherein M is an alkali metal, m is greater than 0 and lessthan 1, M′ is any metal, and n is greater than 0 and less than or equalto 4; and wherein the nanoparticle has a diameter of from about 0.1 nmto about 500 nm.
 5. The multi-fluid kit of claim 1 further comprising:at least one color agent.
 6. The multi-fluid kit of claim 1, wherein thesecond fusing agent comprises a near infrared absorbing compound.
 7. Themulti-fluid kit of claim 6, wherein the near infrared absorbing compoundis selected from the group consisting of carbon black, oxonol,squarylium, chalcogenopyrylarylidene, bis(chalcogenopyrylo)polymethine,bis(aminoaryl)polymethine, merocyanine, trinuclear cyanine,indene-crosslinked polymethine, oxyindolidine, iron complexes, quinoids,nickel-dithiolene complex, cyanine dyes, and combinations thereof. 8.The multi-fluid kit of claim 1, wherein the detailing agent comprises atleast 70 wt % water based on the total weight of the detailing agent. 9.The multi-fluid kit of claim 5, wherein the color agent comprises: acyan ink agent; a yellow ink agent; a magenta ink agent; and a black inkagent.
 10. A three-dimensional printing kit comprising: a powder buildmaterial, wherein the powder build material is selected from the groupconsisting of polymeric powder, polymeric-ceramic composite powder, andcombinations thereof; a marking agent comprising a marking componentwhich is a fluorescent color agent that is activated by ultravioletradiation to emit light in the visible range of from about 400 nm toabout 780 nm; a first fusing agent; and a second fusing agent differentfrom the first fusing agent.
 11. The three-dimensional printing kit ofclaim 10 further comprising: a detailing agent; and at least one coloragent.
 12. The three-dimensional printing kit of claim 10, wherein: thefluorescent color agent is activated by ultraviolet radiation in therange of from about 200 nm to about 400 nm; and the fluorescent coloragent compriseshexasodium-2,2′-[vinylenebis[3-sulfonato-4,1-phenylene)imino[6-(diethylamino)-1,3,5-triazine4,2-diyl]imino]]bis(benzene-1,4-disulphonate).13. A method of using the three-dimensional printing kit of claim 10comprising: adding the powder build material, the marking agent, thefirst fusing agent, and the second fusing agent of claim 10 to athree-dimensional printer; and printing a three-dimensional part.
 14. Amethod for three-dimensional printing comprising: (i) depositing a layerof a polymeric powder build material on a build platform; (ii) based ona 3D object model, selectively applying a first fusing agent, a secondfusing agent different from the first fusing agent, a marking agent, adetailing agent, and at least one coloring agent, to at least a portionof the layer of the polymeric powder build material; (iii) repeating (i)and (ii) at least one time to form an intermediate part; and (iv)heating the intermediate part to a temperature of up to about 180° C. toform a three-dimensional printed part, wherein the marking agentcomprises a marking component which is a fluorescent color agent that isactivated by ultraviolet radiation to emit light in the visible range offrom about 400 nm to about 780 nm.
 15. The method of claim 14 furthercomprising: decaking the three-dimensional printed part.